Glycemic control during TB treatment among Filipinos: The Starting Anti-Tuberculosis Treatment Cohort Study

Poor TB treatment outcomes are observed in patients with type 2 diabetes mellitus (DM) comorbidity and glycemic control throughout treatment may play a role. The objective of this study was to investigate glycemic control longitudinally among Filipino adults undergoing TB treatment using mixed-effects linear and logistic regression. Analyses were conducted in 188 DM-TB patients out of 901 enrolled in the Starting Anti-TB Treatment (St-ATT) cohort, with a median baseline glycosylated hemoglobin (HbA1c) of 8.2% (range 4.5-13.3%). Previous versus new DM diagnosis was associated with higher mean HbA1c (worse glycemic control) during treatment, with a smaller effect amongst those with central obesity (coefficient 0.80, 95% confidence interval [CI] 0.26, 1.57, P = 0.043) than amongst those without central obesity (coefficient 3.48, 95% CI 2.16, 4.80, P<0.001). In those with a new DM diagnosis, central obesity was associated with higher blood glucose (coefficient 1.62, 95% CI 0.72, 2.53, P = 0.009). Of 177 participants with ≥2 HbA1c results, 40% had uncontrolled glycemia (≥2 HbA1c results ≥8%). Of 165 participants with ≥3 HbA1c results, 29.9% had consistently-controlled glycemia, 15.3% had initially-uncontrolled glycemia, and 18.6% had consistently-uncontrolled glycemia. Previous versus new DM diagnosis and glucose-lowering medication use versus no use were associated with having uncontrolled versus controlled glycemia (adjusted odds ratio [aOR] 2.50 95%CI 1.61, 6.05, P = 0.042; aOR 4.78 95% CI 1.61,14.23, P<0.001) and more likely to have consistently-uncontrolled versus consistently-controlled glycemia (adjusted relative risk ratio [aRRR] 5.14 95% CI 1.37, 19.20, P = 0.015; aRRR 10.24 95% CI 0.07, 0.95, P = 0.003). Relapse cases of TB were less likely than new cases to have uncontrolled (aOR 0.20 95%CI 0.06, 0.63, P = 0.031) or consistently-uncontrolled (aRRR 0.25 95%CI 0.07, 0.95, P = 0.042) versus controlled glycemia. Those with long-term DM, suggested by previous diagnosis, glucose-lowering medication use and possibly central obesity, may require additional support to manage blood glucose during TB treatment.

Evaluation of cytokine profiles related to Mycobacterium tuberculosis latent antigens using a whole-blood assay in the Philippines

Introduction

There is no useful method to discriminate between latent tuberculosis infection (LTBI) and active pulmonary tuberculosis (PTB). This study aimed to investigate the potential of cytokine profiles to discriminate between LTBI and active PTB using whole-blood stimulation with Mycobacterium tuberculosis (MTB) antigens, including latency-associated antigens.

Materials and methods

Patients with active PTB, household contacts of active PTB patients and community exposure subjects were recruited in Manila, the Philippines. Peripheral blood was collected from the participants and used for whole-blood stimulation (WBS) with either the early secretory antigenic target and the 10-kDa culture filtrate protein (ESAT-6/CFP-10), Rv3879c or latency-associated MTB antigens, including mycobacterial DNA-binding protein 1 (MDP-1), α-crystallin (Acr) and heparin-binding hemagglutinin (HBHA). Multiple cytokine concentrations were analyzed using the Bio-Plex™ multiplex cytokine assay.

Results

A total of 78 participants consisting of 15 active PTB patients, 48 household contacts and 15 community exposure subjects were eligible. The MDP-1-specific IFN-γ level in the active PTB group was significantly lower than that in the household contact group (p < 0.001) and the community exposure group (p < 0.001). The Acr-specific TNF-α and IL-10 levels in the active PTB group were significantly higher than those in the household contact (TNF-α; p = 0.001, IL-10; p = 0.001) and community exposure (TNF-α; p < 0.001, IL-10; p = 0.01) groups. However, there was no significant difference in the ESAT-6/CFP-10-specific IFN-γ levels among the groups.

Conclusion

The patterns of cytokine profiles induced by latency-associated MTB antigens using WBS have the potential to discriminate between LTBI and active PTB. In particular, combinations of IFN-γ and MDP-1, TNF-α and Acr, and IL-10 and Acr are promising. This study provides the first demonstration of the utility of MDP-1-specific cytokine responses in WBS.

Comparing disease specific catastrophic cost estimates using longitudinal and cross-sectional designs: The example of tuberculosis

BACKGROUND

There has been an increasing interest in assessing disease-specific catastrophic costs incurred by affected households as part of economic evaluations and to inform joint social/health policies for vulnerable groups. Although the longitudinal study design is the gold standard for estimating disease-specific household costs, many assessments are implemented with a cross-sectional design for pragmatic reasons. We aimed at identifying the potential biases of a cross-sectional design for estimating household cost, using the example of tuberculosis (TB), and exploring optimal approaches for sampling and interpolating cross-sectional cost data to estimate household costs.

METHODS

Data on patient incurred costs, household income and coping strategies were collected from TB patients in Negros Occidental and Cebu in the Philippines between November 2018 and October 2020. The data collection tools were developed by adapting WHO Tuberculosis Patient Cost Surveys: A Handbook into a longitudinal study design. TB-specific catastrophic cost estimates were compared between longitudinal and simulated cross-sectional designs using different random samples from different times points in treatment (intensive and continuation phases).

RESULTS

A total of 530 adult TB patients were enrolled upon TB diagnosis in this study. Using the longitudinal design, the catastrophic cost estimate for TB-affected households was 69 % using the output approach. The catastrophic cost estimates with the simulated cross-sectional design were affected by the reduction and recovery in household income during the episode of TB care and ranged from 40 to 55 %.

CONCLUSION

Using longitudinally collected costs incurred by TB-affected households, we illustrated the potential limitations and implications of estimating household costs using a cross-sectional design. Not capturing changes in household income at multiple time points during the episode of the disease and estimating from inappropriate samples may result in biases that underestimates catastrophic cost.

Costs incurred by people with co-morbid tuberculosis and diabetes and their households in the Philippines

OBJECTIVE

Diabetes is a risk factor for TB mortality and relapse. The Philippines has a high TB incidence with co-morbid diabetes. This study assessed the pre- and post-TB diagnosis costs incurred by people with TB and diabetes (TB-DM) and their households in the Philippines.

METHODS

Longitudinal data was collected for costs, income, and coping mechanisms of TB-affected households in Negros Occidental and Cebu, the Philippines. Data collection was conducted four times during TB treatment. The data collection tools were developed by adapting WHO's cross-sectional questionnaire in the Tuberculosis Patient Cost Surveys: A Handbook into a longitudinal study design. Demographic and clinical characteristics, self-reported household income, number of facility visits, patient costs, the proportion of TB-affected households facing catastrophic costs due to TB (>20% of annual household income before TB), coping mechanisms, and social support received were compared by diabetes status at the time of TB diagnosis.

RESULTS

530 people with TB were enrolled in this study, and 144 (27.2%) had TB-DM based on diabetes testing at the time of TB diagnosis. 75.4% of people with TB-DM were more than 45 years old compared to 50.3% of people with TB-only (p<0.001). People with TB-DM had more frequent visits for TB treatment (120 vs 87 visits, p = 0.054) as well as for total visits for TB-DM treatment (129 vs 88 visits, p = 0.010) compared to those with TB-only. There was no significant difference in the proportion of TB-affected households facing catastrophic costs between those with TB-DM (76.3%) and those with TB-only (68.7%, p = 0.691).

CONCLUSION

People with TB-DM in the Philippines face extensive health service use. However, this does not translate into substantial differences in the incidence of catastrophic cost. Further study is required to understand the incidence of catastrophic costs due to diabetes-only in the Philippines.

How can tuberculosis services better support patients with a diabetes co-morbidity? A mixed methods study in the Philippines

BACKGROUND

People with diabetes mellitus (DM) have an estimated two- to three-times greater risk of adverse tuberculosis (TB) treatment outcomes compared to those without DM. Blood glucose control is a primary aim of managing DM during TB treatment, yet TB programmes are not generally adapted to provide DM services. The purpose of this study was to understand perceptions and the lived experiences of diabetic patients in TB treatment in the Philippines, with a view to informing the development of disease co-management strategies.

METHODS

This mixed methods study was conducted within a prospective cohort of adults newly-starting treatment for drug-sensitive and drug-resistant TB at 13 public TB clinics in three regions of the Philippines. Within the subset of 189 diabetic persons who self-reported a prior DM diagnosis, or were diagnosed by screenings conducted through the TB clinic, longitudinal blood glucose data were used to ascertain individuals' glycaemic control (controlled or uncontrolled). Univariable logistic regression analyses exploring associations between uncontrolled glycaemia and demographic and clinical factors informed purposive sampling of 31 people to participate in semi-structured interviews. All audio-recorded data were transcribed and thematic analysis performed.

RESULTS

Participants - both with controlled and uncontrolled blood glucose - were knowledgeable about diabetes and its management. However, a minority of participants were aware of the impact of DM on TB treatment and outcomes. Many participants newly-diagnosed with DM at enrolment in TB treatment had not perceived any diabetic symptoms prior and would have likely not sought clinical consult otherwise. Access to free glucose-lowering medications through TB clinics was a key enabling resource. However, participants expressed fear of side effects and interrupted access to glucose-lowering medications, and a preference for phytotherapy. Many participants felt that physical and financial impacts of TB and its treatment were challenges to DM management.

CONCLUSIONS AND RECOMMENDATIONS

Results of this study indicate that public TB clinics can provide diabetic patients with additional health care resources and education to address co-morbidity. TB programmes might consider identifying patients with complicated DM, and offering diabetic monitoring and management, as DM and diabetic complications may compound the burden of TB and its treatment.

Depression, Nutrition, and Adherence to Antiretroviral Therapy in Men Who Have Sex With Men in Manila, Philippines

Introduction: Depression is the most frequently observed psychiatric disorder among HIV patients. The effect of depression on adherence among men who have sex with men (MSM) HIV patients has not been well studied in the Philippines. Depression is commonly undiagnosed and consequently untreated, which leads to a negative influence on antiretroviral therapy (ART) adherence. Other risk factors such as HIV-related stigma, self-body image satisfaction, and nutritional status are recognized as potential barriers to access HIV prevention and treatment services issues and poor adherence.

Methods: Hospital anxiety and depression scale (HADS) was used to screen depressive symptoms during scheduled clinic visits. ART adherence was self-reported using a visual analog scale questionnaire covering the last 30 days. Structured questionnaires were used for measuring risk factors and socio-demographic data. Anthropometry was conducted and body composition was assessed using bioelectrical impedance analysis.

Results: One-hundred and ninety-three participants were recruited from the SHIP clinic between 7th March and 30th September 2018, of whom, 42 (21.8%) screened positive for depression (HADS score ≥ 8) and 24 (12.4%) were non-adherent to ART (<95% of medication taken as prescribed). The most common reported reason for non-adherence was simply forgotten (18 out of 42, 42.9%). Increasing depressive symptoms were associated with non-adherence [crude odds ratio (OR) = 1.13; 95% CI: 1.02–1.26]. Social family support (SFS) and body image (BI) scores were also associated with non-adherence, but were not statistically significant in multivariable models. Factors significantly associated with depressive symptoms (but not non-adherence) included the following: using intravenous drugs, being in a relationship, anxiety, self-esteem, and stigma scores.

Conclusions: Increased depression symptoms, low social family support, and body image dissatisfaction may be interconnected risk factors for ART non-adherence among Filipino MSM HIV patients. Comprehensive mental health services beyond regular post-HIV testing counseling may increase adherence to ART and improve HIV treatment outcomes. Further prospective studies are needed to address the causal/reverse causal pathway between depression and non-adherence.

Experiences, challenges and looking to the future in a clinical tuberculosis cohort in the time of COVID-19 in the Philippines

A cohort study of Filipino tuberculosis patients is currently undergoing data collection amidst the coronavirus disease 2019 pandemic. In this article we present the current experiences, challenges and obstacles of our team during this period as we attempt to fulfil our roles and responsibilities in Metro Manila, Cebu and Negros Occidental in the Philippines. Each site had different lockdown restrictions and experienced problems to different degrees. The underlying themes were similar, covering the supply chain, mobility, communication, physical and mental health and disruption of health services due to reallocation of staff. While we maximized the use of mobile devices, logistical challenges remained. Institutional support for the field teams, creative problem solving and resilience are required to adapt in a rapidly changing environment.

An observational report of universal GeneXpert testing of inpatients with diagnosed or presumptive TB in the Philippines

Background

The Philippines is a high TB and multidrug-resistant TB burden country. Although the scale-up of GeneXpert testing is occurring, the benefits of universal Xpert-Mycobacterium tuberculosis/ rifampicin (MTB/RIF) testing in inpatients have not been documented.

Methods

Routine GeneXpert testing irrespective of priority criteria for testing was conducted within a prospective cohort of all adults with known or presumptive TB admitted to a tertiary infectious diseases hospital in Manila. Study-specific TB diagnosis was decided upon bacteriological results, chest x-ray assessment, if already on anti-TB treatment (ATT) at admission and a cough duration of ≥2 wk.

Results

Of submitted sputum samples, 87.1% (277/318) had valid acid-fast bacilli (AFB) microscopy and Xpert® MTB/RIF results. Xpert® MTB/RIF was positive in 97.7% (n = 87/89) of AFB-positive patients and 25.5% (n = 48/188) of AFB-negative patients. Bacteriological confirmation in smear negative cases not on ATT prior to admission was 25.2% (34/135). Rifampicin resistance was detected in 26/135 Xpert positive cases (19.3%), including nine who might not otherwise have been detected, representing a 53% increase in yield.

Conclusion

Universal GeneXpert testing in this setting enhanced the yield of bacterial confirmation, revealing a high incidence of rifampicin resistance and suggesting a need for further investigations in Xpert-negative/smear-positive patients who may not have mycobacterial TB.

Frequent unregulated use of antibiotics in rural Cambodian infants

Background

Despite a high prevalence of antibiotic resistance in Cambodia, few studies have assessed health-seeking behaviour and the use of antibiotics by caregivers of young children in Cambodia.

Methods

We conducted a cross-sectional survey of infants <12 months of age and their caregivers, assessing the frequency of reported illness, common symptoms and associated health-seeking behaviour through structured questionnaires administered by trained fieldworkers at a home visit. In a subset of these participants, ages 4–8 months with no acute malnutrition, we conducted a 3-month surveillance with fortnightly home visits.

Results

Of 149 infants (ages 1–11 months, 54.4% male) enrolled in the cross-sectional study, 76 (51.4%) reported symptoms of diarrhoea, fever or cough in the previous 14 d, with associated use of antibiotics reported in 22 (14.8%) infants. In 47 infants enrolled in the longitudinal surveillance, there were 141 reported episodes of illness in 44 (94%) infants with 21 infants (45%) reported to have received antibiotics in 32/141 (22.7%) episodes. Amoxicillin was the most commonly reported antibiotic in both surveys (68% [40/59 episodes reporting the use of antibiotics]).

Conclusions

Antibiotic usage is high in this population and appears to be occurring largely outside of the formal healthcare system.

Depression and its associated factors among people with multidrug-resistant tuberculosis in Myanmar

BACKGROUND

Depression is an important potential comorbidity in persons with tuberculosis (TB), yet data in many settings are scarce.

OBJECTIVE

To estimate the prevalence and risk factors of depression in persons with multidrug-resistant tuberculosis (MDR-TB) in Myanmar.

METHODS

A cross-sectional survey among MDR-TB participants at Aung San MDR-TB treatment centre in Yangon during routine clinic follow-up visits. Patients Health Questionnaire-9 (PHQ-9) in the local language was used to screen for depression and structured questionnaires conducted. Univariable and multivariable logistic regression models were performed to identify associations.

RESULTS

Three-hundred and twenty-nine participants were enrolled between 19th December 2019 and 31st January 2020; 33% (111/329) in the intensive treatment phase. The prevalence of depressive symptoms (PHQ-9 ≥ 10) was (34/329) 10.33%. Multivariable analysis indicated financial hardship as a result of MDR-TB symptoms/treatment (aOR = 2.63, 95%CI: 1.12-6.67), suffering ≥1 respiratory symptoms (aOR = 6.72, 95%CI: 2.41-18.76), high education level (aOR = 4.26, 95%CI: 1.70-10.70), reported diabetes (aOR = 3.05, 95%CI: 1.16-7.99) as associated with depressive symptoms, with weak evidence of an association in females (aOR = 2.09, 95%CI: 0.94-4.65).

CONCLUSION

Depressive symptoms are more common in those with comorbidities/TB symptoms. Further research is required to determine the effects of interventions to support persons with depressive symptoms identified using simple, standardised validated tools like PHQ-9.

Determinants of growth measurements in rural Cambodian infants: a cross-sectional study

Background

Inappropriate feeding and hygiene practices and poor environment are associated with malnutrition. We aimed to investigate the contributions of feeding, hygiene practices and recent illness to the nutritional status of rural Cambodian infants and any sex-specific differences.

Methods

In a cross-sectional study, nested within an ongoing birth cohort, trained fieldworkers conducted anthropometry and collected information from the main caregiver during home visits. Multivariable linear regression was used to investigate associations with nutritional status as length-for-age z-scores (LAZ) and weight-for-length z-scores (WLZ).

Results

A total of 156 children, 87 (55.8%) male, ages 0–11 months were enrolled. The prevalence of acute malnutrition (WLZ <−2) in males and females was 2.3% (2/87) and 5.8% (4/69), respectively, and 23.0% (20/87) of males and 14.5% (10/69) of females were stunted (LAZ <−2). WLZ but not LAZ decreased with age. WLZ was independently negatively associated with increasing age (β-coefficient −0.14 [95% confidence interval {CI} −0.20 to −0.08], p<0.001), and regular use of feeding bottles (β-coefficient −0.46 [95% CI −0.83 to −0.10], p=0.014), and positively with handwashing with soap (β-coefficient 0.40 [95% CI 0.05 to 0.75), p=0.027).

Conclusions

The prevalence of acute malnutrition was low, but stunting was prevalent without evidence of a sex difference. Non-linear growth faltering was associated with increasing age and hygiene/feeding practices.

Patterns of non-communicable comorbidities at start of tuberculosis treatment in three regions of the Philippines: The St-ATT cohort

Diabetes and undernutrition are common risk factors for tuberculosis (TB), associated with poor treatment outcomes and exacerbated by TB. Limited data exist describing patterns and risk factors of multiple comorbidities in persons with TB. Nine-hundred participants (69.6% male) were enrolled in the Starting Anti-TB Treatment (St-ATT) cohort, including 133 (14.8%) initiating treatment for multi-drug resistant TB (MDR-TB). Comorbidities were defined as: diabetes, HbA1c ≥6.5% and/or on medication; hypertension, systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg and/or on medication; anaemia (moderate/severe), haemoglobin <11g/dL; and, undernutrition (moderate/severe) body-mass-index <17 kg/m2. The most common comorbidities were undernutrition 23.4% (210/899), diabetes 22.5% (199/881), hypertension 19.0% (164/864) and anaemia 13.5% (121/899). Fifty-eight percent had ≥1 comorbid condition (496/847), with 17.1% having ≥2; most frequently diabetes and hypertension (N = 57, 6.7%). Just over half of diabetes (54.8%) and hypertension (54.9%) was previously undiagnosed. Poor glycemic control in those on medication (HbA1c≥8.0%) was common (N = 50/73, 68.5%). MDR-TB treatment was associated with increased odds of diabetes (Adjusted odds ratio (AOR) = 2.48, 95% CI: 1.55-3.95); but decreased odds of hypertension (AOR = 0.55, 95% CI: 0.39-0.78). HIV infection was only associated with anaemia (AOR = 4.51, 95% CI: 1.01-20.1). Previous TB treatment was associated with moderate/severe undernutrition (AOR = 1.98, 95% CI: 1.40-2.80), as was duration of TB-symptoms before starting treatment and household food insecurity. No associations for sex, alcohol or tobacco use were observed. MDR-TB treatment was marginally associated with having ≥2 comorbidities (OR = 1.52, 95% CI: 0.97-2.39). TB treatment programmes should plan for large proportions of persons requiring diagnosis and management of comorbidities with the potential to adversely affect TB treatment outcomes and quality of life. Dietary advice and nutritional management are components of comprehensive care for the above conditions as well as TB and should be included in planning of patient-centred services.

Prevalence and risk factors of Schistosoma mansoni infection among children under two years of age in Mbita, Western Kenya

Despite growing evidence that infants and very young children can be infected with schistosomes, the epidemiological features and risk factors are not well described in this age group. We aimed to assess the prevalence of S. mansoni infection in children under two years of age from a population with a known high burden of infection in school-aged children and adults and thus inform the need for interventions in this potentially vulnerable age group. In a cross-sectional study in Mbita Sub-county, along the east coast of Lake Victoria, Western Kenya, we enrolled 361 children aged 6-23 months. The prevalence of S. mansoni infection was detected using the Kato-Katz stool examination and a point-of-care test for urinary circulating cathodic antigen (POC-CCA) (Rapid Medical Diagnostics, Pretoria, South Africa). Three-hundred and five (305) children had complete data of whom 276 (90.5%, 95%CI: 86.6-93.5) children were positive for S. mansoni by the POC-CCA test, while 11 (3.6%, 95%CI: 1.8-6.4) were positive by the Kato-Katz method. All Kato-Katz positive cases were also positive by the POC-CCA test. In multivariable analysis, only geographical area, Rusinga West (AOR = 7.1, 95%CI: 1.4-35.2, P = 0.02), was associated with S. mansoni infection using Kato-Katz test. Independent associations for POC-CCA positivity included age, (12-17 months vs 6-11 months; AOR = 7.8, 95%CI: 1.8-32.6, P = 0.002) and breastfeeding in the previous 24 hours (AOR = 3.4, 95%CI: 1.3-9.0, P = 0.009). We found a potentially very high prevalence of S. mansoni infection among children under two years of age based on POC-CCA test results in Mbita Sub-county, Kenya, which if confirmed strongly supports the need to include infants in public health strategies providing universal prophylactic treatment in high burden settings. Further research is required to determine the accuracy of diagnostic tools to detect light infection among very young children and possible long-term health impacts.

L-Glutamine in sickle cell disease

L-Glutamine is a conditionally essential amino acid required for synthesis of the pyridines for nucleotides, including nicotinamide adenine dinucleotide (NAD) and glutathione, as well as glutamate, and becomes essential during oxidative stress exposure. The NADH:[NAD⁺ + NADH] (redox) ratio in sickle red blood cells (RBCs) is lower than in normal RBCs, consistent with oxidative stress, therefore glutamine availability is important in sickle cell disease (SCD). RBC glutamine levels vary between SCD studies but the ratio glutamine:glutamate was inversely related to tricuspid regurgitant jet velocity in one. Oral L-glutamine was associated with an increase in NADH and reduction in RBC endothelium adhesion in small studies of SCD patients. In a sickle mouse model, glutamine levels were directly related to cerebral blood flow. Phase II and III randomized, double-blind, controlled trials of L-glutamine 0.6 g/kg/day compared with placebo in children and adults with SCD and = 2 episodes of pain in the previous year provide evidence that L-glutamine is safe and associated with a reduction in painful episodes and in hospitalizations. However, L-glutamine was only tolerated in two-thirds of patients, anemia and hemolysis did not improve and there are few data on mortality and organ complications. Future studies should investigate the effect of other amino acids and total protein intake.

Effects of comorbidities on quality of life in Filipino people with tuberculosis

BACKGROUND: We investigated health-related quality of life (HrQoL) in Filipino people undergoing TB treatment, and whether HrQoL was negatively impacted by comorbidity with undernutrition, diabetes (DM) and anaemia.METHODS: Adult participants were enrolled in public facilities in Metro Manila (three sites) and Negros Occidental (two sites). Multivariate linear regression was used to model the four correlated domain scores from a WHOQOL-BREF questionnaire (physical, psychological, social, environmental). A forward-stepwise approach was used to select a final multivariable model with inclusion based on global tests of significance at P < 0.1.RESULTS: In 446 people on drug-susceptible TB treatment, DM and moderate/severe anaemia were not associated with HrQoL. After adjustment for age, sex, education, food insecurity, treatment adherence, inflammation, Category I or II TB treatment, treatment phase, current side effects and inhibited ability to work, moderate/severe undernutrition (body mass index < 17 kg/m²) was associated with lower HrQoL (P = 0.003) with reduced psychological (coefficient: -1.02, 95% CI -1.54 to -0.51), physical (-0.62, 95% CI -1.14 to -0.09) and environmental domain scores (-0.45, 95% CI -0.88 to -0.01). In 225 patients with known HIV status in Metro Manila, HIV was associated with modestly reduced HrQoL (P = 0.014).CONCLUSION: Nutritional status and food insecurity represent modifiable risk factors for poor HrQoL that may be alleviated through interventions.

Patterns and predictors of co-morbidities in Tuberculosis: A cross-sectional study in the Philippines

Diabetes and undernutrition are common risk factors for TB, associated with poor treatment outcomes and exacerbated by TB. We aimed to assess non-communicable multimorbidity (co-occurrence of two or more medical conditions) in Filipino TB outpatients, focusing on malnutrition and diabetes. In a cross-sectional study, 637 adults (70% male) from clinics in urban Metro Manila (N = 338) and rural Negros Occidental (N = 299) were enrolled. Diabetes was defined as HbA1c of ≥6.5% and/or current diabetes medication. Study-specific HIV screening was conducted. The prevalence of diabetes was 9.2% (54/589, 95%CI: 7.0-11.8%) with 52% newly diagnosed. Moderate/severe undernutrition (body mass index (BMI) <17 kg/2) was 20.5% (130/634, 95%CI: 17.4-23.9%). Forty percent of participants had at least one co-morbidity (diabetes, moderate/severe undernutrition or moderate/severe anaemia (haemoglobin <11 g/dL)). HIV infection (24.4%, 74/303) was not associated with other co-morbidities (but high refusal in rural clinics). Central obesity assessed by waist-to-hip ratio was more strongly associated with diabetes (Adjusted Odds Ratio (AOR) = 6.16, 95%CI: 3.15-12.0) than BMI. Undernutrition was less common in men (AOR = 0.44, 95%CI: 0.28-0.70), and associated with previous history of TB (AOR = 1.97, 95%CI: 1.28-3.04) and recent reduced food intake. The prevalence of multimorbidity was high demonstrating a significant unmet need. HIV was not a risk factor for increased non-communicable multimorbidity.

Newborn screening for sickle cell disease: an innovative pilot program to improve child survival in Dar es Salaam, Tanzania

BACKGROUND

Sickle cell disease (SCD) is a recognized cause of childhood mortality. Tanzania has the fifth highest incidence of SCD (with an estimated 11 000 SCD annual births) worldwide. Although newborn screening (NBS) for SCD and comprehensive healthcare have been shown to reduce under-5 mortality by up to 94% in high-income countries such as the USA, no country in Africa has maintained NBS for SCD as a national health program. The aims of this program were to establish and evaluate NBS-SCD as a health intervention in Tanzania and to determine the birth prevalence of SCD.

METHODS

Muhimbili University of Health and Allied Sciences conducted NBS for SCD from January 2015 to November 2016. Dried blood spot samples were collected and tested for SCD using isoelectric focusing.

RESULTS

Screening was conducted on 3981 newborns. Thirty-one (0.8%) babies had SCD, 505 (12.6%) had sickle cell trait and 26 (0.7%) had other hemoglobinopathies. Twenty-eight (90.3%) of the 31 newborns with SCD were enrolled for comprehensive healthcare.

CONCLUSIONS

This is the first report on NBS as a health program for SCD in Tanzania. The SCD birth prevalence of 8 per 1000 births is of public health significance. It is therefore important to conduct NBS for SCD with enrollment into a comprehensive care program.

Does capitation affect patient satisfaction and prevalence of out-of-pocket payments in the insured? A propensity score analysis of Ghana's demographic and health survey data

Background

Ghana’s National Health Insurance Scheme (NHIS) piloted capitation payment for primary care services in the Ashanti region from 2012 to 2017. Capitation was piloted as a means of cost containment but also to induce managed competition among health providers to improve the responsiveness of healthcare delivery. This study examined the effects of exposure to capitation on perceived health service quality and prevalence of out-of-pocket payments in NHIS insured clients.

Methods

Respondents of the 2014 Ghana Demographic and Health Survey (G-DHS) who reported having a valid NHIS card as their only form of health insurance coverage and made a health facility visit within the 6 months prior to the survey were used to assess the exposure effects of capitation on four outcomes: overall patient satisfaction, perceived friendliness of health staff, perceived adequacy of consultation time, and prevalence of out-of-pocket payments. We applied propensity score matching to balance distributions of covariates and to compare outcomes between exposed NHIS insured clients and their unexposed counterparts.

Results

NHIS insured clients exposed to capitation had 10 percentage points higher probability of encountering out-of-pocket payments than their unexposed counterparts (p = 0.009; 95% CI: 2.5–17.8%). There was no evidence of a difference between the two exposure groups for ratings of the three quality perceptions outcomes examined: overall patient satisfaction, difference 0.63 units (p = 0.46); perceived friendliness of health staff, difference 1.1% (p = 0.50); and perceived adequacy of consultation times, difference 0.1% (p = 0.96).

Conclusion

In the Ghanaian context, our results suggest capitation was associated with a greater probability of out-of-pocket payments and no difference in perceived service quality. Future research should examine clinical quality of healthcare and how much out-of-pocket payment occurred under capitation.

Mid-upper arm circumference predicts death in adult patients admitted to a TB ward in the Philippines: A prospective cohort study

Background

The Philippines is ranked 3^rd globally for tuberculosis incidence (554/100,000 population). The tuberculosis ward at San Lazaro Hospital, Manila receives 1,800–2,000 admissions of acutely unwell patients per year with high mortality. Objectives of this prospective cohort study were to quantify the association of under-nutrition (primary) and diabetes (secondary) with inpatient mortality occurring between 3–28 days of hospital admission in patients with suspected or previously diagnosed TB.

Methods and results

We enrolled 360 adults (≥18 years); 348 were eligible for the primary analysis (alive on day 3). Clinical, laboratory, anthropometric and enhanced tuberculosis diagnostic data were collected at admission with telephone tracing for mortality up to 6 months post-discharge. In the primary analysis population (mean age 45 years, SD = 15.0 years, 70% male), 58 (16.7%) deaths occurred between day 3–28 of admission; 70 (20.1%) between day 3 and discharge and documented total post-day 3 mortality including follow-up was 96 (27.6%). In those in whom it could be assessed, body mass index (BMI) ranged from 11.2–30.6 kg/m² and 141/303 (46.5%) had moderate/severe undernutrition (BMI<17 kg/m²). A sex-specific cut-off for mid-upper arm circumference predictive of BMI<17 kg/m² was associated with inpatient Day 3–28 mortality in males (AOR = 5.04, 95% CI: 1.50–16.86; p = 0.009; p = 0.032 for interaction by sex). The inability to stand for weight/height for BMI assessment was also associated with mortality (AOR = 5.59; 95% CI 2.25–13.89; p<0.001) as was severe compared to normal/mild anaemia (AOR = 9.67; 95% CI 2.48–37.76; p<0.001). No TB specific variables were associated with Day 3–28 mortality, nor was diabetes (HbA1c ≥6.5% or diabetes treatment). Similar effects were observed when the same multivariable model was applied to confirmed TB patients only and to the outcome of all post-day 3 in-patient mortality.

Conclusion

This research supports the use of mid-upper arm circumference for triaging acutely unwell patients and the design and testing of nutrition-based interventions to improve patient outcomes.

Transcranial Doppler and Magnetic Resonance in Tanzanian Children With Sickle Cell Disease

Supplemental Digital Content is available in the text.

Background and Purpose—

We determined prevalences of neurological complications, vascular abnormality, and infarction in Tanzanian children with sickle cell disease.

Methods—

Children with sickle cell disease were consecutively enrolled for transcranial Doppler; those with slightly elevated (>150 cm/s), low (<50 cm/s) or absent cerebral blood flow velocity (CBFv) were invited for brain magnetic resonance imaging and magnetic resonance angiography.

Results—

Of 200 children (median age 9; range 6–13 years; 105 [2.5%] boys), 21 (11%) and 15 (8%) had previous seizures and unilateral weakness, respectively. Twenty-eight (14%) had elevated and 39 (20%) had low/absent CBFv, all associated with lower hemoglobin level, but not higher indirect bilirubin level. On multivariable analysis, CBFv>150 cm/s was associated with frequent painful crises and low hemoglobin level. Absent/low CBFv was associated with low hemoglobin level and history of unilateral weakness. In 49 out of 67 children with low/absent/elevated transcranial Doppler undergoing magnetic resonance imaging, 43% had infarction, whereas 24 out of 48 (50%) magnetic resonance angiographies were abnormal. One had hemorrhagic infarction; none had microbleeds. Posterior circulation infarcts occurred in 14%. Of 11 children with previous seizure undergoing magnetic resonance imaging, 10 (91%) had infarction (5 silent) compared with 11 out of 38 (29%) of the remainder (P=0.003). Of 7 children with clinical stroke, 2 had recurrent stroke and 3 died; 4 out of 5 had absent CBFv. Of 193 without stroke, 1 died and 1 had a stroke; both had absent CBFv.

Conclusions—

In one-third of Tanzanian children with sickle cell disease, CBFv is outside the normal range, associated with frequent painful crises and low hemoglobin level, but not hemolysis. Half have abnormal magnetic resonance angiography. African children with sickle cell disease should be evaluated with transcranial Doppler; those with low/absent/elevated CBFv should undergo magnetic resonance imaging/magnetic resonance angiography.

Coronary heart disease and stroke disease burden attributable to fruit and vegetable intake in Japan: projected DALYS to 2060

BACKGROUND

Fruit and vegetable consumption was considered a protective effect against cardiovascular and cerebrovascular diseases (CVDs). This study aimed to project the reduction in the CVD burden under different scenarios of increased fruit and vegetable intake in Japan by 2060.

METHODS

Population attributable fractions (PAF) were calculated by gender and age in 2015. The projection considered five scenarios for 2015, 2030, 2045, and 2060: 1) a baseline of no changes in intake; 2) a moderate increase in fruit intake (extra 50 g/day or 1/2 serving); 3) an high increase in fruit intake (extra 100 g/day or 1 serving); 4) a moderate increase in vegetable intake (extra 70 g/day or 1 serving); and 5) an high increase in vegetable intake (extra 140 g/day or 2 servings). Potentially preventable disability-adjusted life years (DALYs) for CVDs were estimated for each scenario. Monte Carlo simulations were performed to calculate the 95% confidence intervals of the estimates.

RESULTS

Across all age groups, men had a higher daily vegetable intake than women (292.7 g/d > 279.3 g/d) but a lower daily fruit intake (99.3 g/d < 121.0 g/d). Comparing with recommended intake level (350 g/d of vegetable and 200 g/d of fruit), the total CVD burden was estimated to be 302,055 DALYs attributable to inadequate fruit consumption in 2015, which accounted for 12.6% of the total CVD burden (vegetable: 202,651 DALYs; 8.5%). In 2060, the percentage of the CVD burden due to insufficient intake of fruit is estimated to decrease to 7.9% under the moderate increase scenario and to decrease to 4.5% under the high increase scenario (vegetable: 5.4%; 2.4%).

CONCLUSIONS

The study suggested that a relevantly large percentage of the CVD burden can be alleviated by promoting even modest increases in fruit and vegetable consumption in Japan.

Performance of alternative measures to body mass index in the assessment of moderate and severe under-nutrition among acutely unwell patients hospitalized in a TB ward in the Philippines: A cross-sectional study

Body mass index (BMI) kg/m2 is a key screening tool for under-nutrition in adults, but difficult to obtain in immobile or unwell patients, particuarly in low resource settings, due to inability to accurately measure both weight and height. Mid-upper arm circumference (MUAC) is used to assess under-nutrition in children under 5 years but no standardised cut-off values exist for adults. In a cohort of adult Filipino patients admitted to a tuberculosis ward we assessed (i) cut-offs for MUAC to predict moderate under-nutrition (BMI <17kg/m2), (ii) the performance of limb lengths to predict height and; (iii) associations of body fat percentage from skinfolds and hand grip-strength with BMI. In 303 patients with MUAC and BMI at admission, aged 18-80 years (mean = 45.5, SD:14.8), BMI ranged from 11.2-30.6 kg/m2 and 141 (46.5%) had BMI <17.0 kg/m2. Using receiver operator curves, MUAC cut-offs were identified as <20.5cm for males (sensitivity: 89%, specificity: 84%) and <18.5cm for females (sensitivity: 91%, specificity: 89%), for BMI<17.0 kg/m2. Using published equations, knee height had the lowest mean difference between predicted and measured heights compared to ulnar or demi-span: (-0.98 cm, 95% CI: -1.51/-0.44). Both grip-strength and body fat percentage were positively associated with BMI, in separate linear regression models with exposure-age-sex interactions (adjusted-R-squared values: 0.15, 0.66, respectively). MUAC can predict moderate acute under-nutrition with high positive predictive value. Further research is required to determine the performance of alternative measures to BMI to predict mortality or adverse outcomes in acutely unwell patients.

Serum Calcium Concentrations, Chronic Inflammation and Glucose Metabolism: A Cross-Sectional Analysis in the Andhra Pradesh Children and Parents Study (APCaPS)

BACKGROUND

Evidence suggests a role for elevated serum calcium in dysregulated glucose metabolism, linked through low-level chronic inflammation.

OBJECTIVES

We investigated the association of elevated serum calcium concentrations (corrected for albumin) with markers of dysregulated glucose metabolism and type II diabetes and tested if these associations were accounted for by chronic inflammation in a rural Indian population.

METHODS

A cross-sectional analysis of participants aged 40-84 y from the Andhra Pradesh Children and Parents Study (APCaPS; n = 2699, 52.2% women) was conducted. Comprehensive information on household, sociodemographic, and lifestyle factors; medical and family history; physical measurements; blood measurements including fasting plasma glucose (FPG), fasting insulin (FI), serum calcium, albumin, phosphorous, vitamin D (in a subset), and creatinine were analyzed. Additionally, in a random sample of healthy participants (n = 1000), inflammatory biomarkers (interleukins 6 and 18, soluble intercellular adhesion molecule 1, adiponectin, and high-sensitivity C-reactive protein) were measured and an inflammatory score (IScore) calculated.

RESULTS

After adjustments for sociodemographics, lifestyle factors, and anthropometry the highest calcium quartile (Q4 compared with Q1) was associated with FI (β = 1.4 µU/ml; 95% CI: 1.2, 1.5 µU/ml; P-trend < 0.001), the homeostasis model assessment for insulin resistance (HOMA-IR) (β = 1.4; 95% CI: 1.2, 1.5; P-trend < 0.001), and was modestly associated with FPG (β = 2.1 mg/dL; 95% CI: -0.9, 5.2 mg/dL; P-trend = 0.058) and prevalent type II diabetes (OR = 1.6; 95% CI: 1.0, 2.6; P-trend= 0.020). In the healthy subgroup, the association of the highest calcium quartile was similar for FI and HOMA-IR. Additional adjustment with IScore did not alter the associations. Further, in a subset, all these associations were independent of endogenous regulators of calcium metabolism (serum vitamin D, phosphorus, and creatinine). Independently, after accounting for potential confounders, the highest IScore quartile (Q4 compared with Q1) was positively associated with FPG, FI, HOMA-IR, and prevalent prediabetes, and also with serum calcium concentrations in men.

CONCLUSIONS

Elevated serum calcium was positively associated with markers of dysregulated glucose metabolism and prevalent type II diabetes in a rural Indian population. Chronic inflammation did not mediate this association but was independently associated with markers of dysregulated glucose metabolism. Inflammation might be responsible for elevated serum calcium concentrations in men.

A ten year review of the sickle cell program in Muhimbili National Hospital, Tanzania

Background

Africa has the highest burden of Sickle cell disease (SCD) but there are few large, systematic studies providing reliable descriptions of the disease spectrum. Tanzania, with 11,000 SCD births annually, established the Muhimbili Sickle Cell program aiming to improve understanding of SCD in Africa. We report the profile of SCD seen in the first 10 years at Muhimbili National Hospital (MNH).

Methods

Individuals seen at MNH known or suspected to have SCD were enrolled at clinic and laboratory testing for SCD, haematological and biochemical analyses done. Ethnicity was self-reported. Clinical and laboratory features of SCD were documented. Comparison was made with non-SCD population as well as within 3 different age groups (< 5, 5–17 and ≥ 18 years) within the SCD population.

Results

From 2004 to 2013, 6397 individuals, 3751 (58.6%) SCD patients, were enrolled, the majority (47.4%) in age group 5–17 years. There was variation in the geographical distribution of SCD. Individuals with SCD compared to non-SCD, had significantly lower blood pressure and peripheral oxygen saturation (SpO₂). SCD patients had higher prevalence of severe anemia, jaundice and desaturation (SpO₂ < 95%) as well as higher levels of reticulocytes, white blood cells, platelets and fetal hemoglobin. The main causes of hospitalization for SCD within a 12-month period preceding enrolment were pain (adults), and fever and severe anemia (children). When clinical and laboratory features were compared in SCD within 3 age groups, there was a progressive decrease in the prevalence of splenic enlargement and an increase in prevalence of jaundice. Furthermore, there were significant differences with monotonic trends across age groups in SpO2, hematological and biochemical parameters.

Conclusion

This report confirms that the wide spectrum of clinical expression of SCD observed elsewhere is also present in Tanzania, with non-uniform geographical distribution across the country. Age-specific analysis is consistent with different disease-patterns across the lifespan.

Decreased Hepcidin Levels Are Associated with Low Steady-state Hemoglobin in Children With Sickle Cell Disease in Tanzania

Background

The contribution of hepcidin as a regulator of iron metabolism & erythropoiesis on the severity of anemia in sickle cell disease (SCD) remains poorly characterized, especially in Sub-Saharan African populations. The aims of the study were to determine if hepcidin is associated with severity of steady-state anemia in SCD and to investigate factors associated with hepcidin and anemia in SCD.

Methods

Archived samples from 199 Tanzanian children, 56% boys aged 3–18 with laboratory-confirmed SCD were analysed based on recorded averaged steady-state hemoglobin (ASSH) quartiles (lowest vs. highest). Univariable and multivariable logistic regression was used to assess associations with ASSH quartiles.

Findings

In univariable analysis, hepcidin <5·5 ng/mL was associated with increased odds of being in the lowest ASSH quartile (OR 2·20; 95%CI 1·2–3·93) but which was limited to girls (OR 4·85, 95%CI 1·79–13·09, p = .046 for interaction). In multivariable analyses including either reticulocyte percentage or erythropoietin, lower hepcidin remained significantly associated with lowest ASSH quartile, although the hepcidin-sex interaction no longer reached statistical significance. No associations with ASSH quartile were observed for markers of inflammation, hemolysis or potential iron markers except for microcytosis, associated with higher ASSH, but which was confounded by reticulocyte percentage and alpha-thalassaemia status.

Interpretation

Hepcidin is lower in more severely anaemic children with SCD independent of inflammation or markers of erythropoiesis.

Funding

Funding sources include The Wellcome Trust (080025, 095009, 094780 & 070114), MRC-UK (MC-A760-5QX00), NIHR Oxford Biomedical Research Centre, and the Bill and Melinda Gates Foundation (“Hepcidin and Iron in Global Health”, OPP1055865).

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Low hepcidin levels are associated with severe anemia independent of markers of erythropoiesis and inflammation.

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Low serum ferritin is present in some children but is not associated with severe anemia.

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Although iron markers remain difficult to interpret in sickle cell disease, hepcidin levels were mostly below levels that would be expected to inhibit iron absorption and recycling.

Ready-to-use food supplement, with or without arginine and citrulline, with daily chloroquine in Tanzanian children with sickle-cell disease: a double-blind, random order crossover trial

BACKGROUND

Sickle-cell disease increases the risk of malnutrition. Low arginine and nitric oxide bioavailability are implicated in morbidity related to sickle-cell disease. Simple interventions are required, especially in low-income settings. We aimed to test the hypotheses that: (1) supplementary arginine, citrulline, and daily chloroquine increase bioavailable arginine and flow-mediated dilatation (FMD; maximal diameter change; FMDmax%), a measure of nitric oxide-dependent endothelial function; and (2) protein energy supplementation in the form of ready-to-use supplementary food (RUSF) improves the height-for-age and body-mass index-for-age Z-scores in children with sickle-cell disease.

METHODS

We performed a double-blind, random order crossover trial with two 4-month intervention periods (each followed by 4-month washout periods) in Muhimbili National Hospital in Dar-es-Salaam, Tanzania. We enrolled 119 children from the Muhimbili Sickle Cohort who were aged 8-12 years, naive to hydroxyurea, and had documented HbSS phenotype. Two formulations of RUSF (providing 500 kcal/day) were tested: basic (RUSF-b), with which children also received weekly chloroquine (150 mg or 225 mg chloroquine base, dependent on bodyweight); and vascular (RUSF-v), which was fortified with arginine and citrulline (designed to achieve mean intakes of 0·2 g/kg per day of arginine and 0·1 g/kg per day of citrulline), and with which children received daily chloroquine (maximum 3 mg chloroquine base/kg per day). Children were randomly allocated to receive either RUSF-b first or RUSF-v first and, after a washout period, were then given the other treatment. The primary outcomes in comparing the two RUSF formulations were mean plasma arginine, arginine to ornithine ratio, and arginine to asymmetric dimethylarginine ratio, and mean FMDmax%. The primary outcomes of the combined effect of both RUSF interventions were mean height-for-age Z-score and body-mass index-for-age Z-score. Analyses were done on the eligible intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01718054; and with ISRCTN74331412.

FINDINGS

Between Aug 9, 2012, and Feb 26, 2014, 145 children were randomised (71 children to RUSF-v first and 74 children to RUSF-b first) and 119 children were treated, of whom 114 children yielded complete data for all reported endpoints. The ratio of arginine to ornithine (mean of individual differences -8·67%, 95% CI -19·55 to 2·20; p=0·12) and the mean FMDmax% (1·00, -0·47 to 2·47; p=0·18) did not significantly differ between the RUSF-b and RUSF-v treatments. However, the arginine to asymmetric dimethylarginine ratio was significantly increased by RUSF-v compared with RUSF-b (56·26%, 31·13 to 81·38; p<0·0001). In planned analyses that used mixed effects models to estimate the effect of each intervention compared with the participants at baseline or during washout periods, the arginine to asymmetric dimethylarginine ratio increased following both RUSF-v treatment (86%; p<0·0001) and RUSF-b treatment (40%; p<0·0001). However, FMDmax% was higher after treatment with RUSF-v (0·92; p<0·0001) but not RUSF-b (0·39; p=0·22). Following either intervention (RUSF-b and RUSF-v, pooled) body-mass index-for-age Z-score (0·091; p=0·001) and height-for-age Z-score (0·013; p=0·081) increased compared with baseline and washout timepoints. In 83 participants in the treated population, there were 71 adverse events during the intervention, of which 21 (30%) were serious, and 81 adverse events during the washout periods, of which 26 (32%) were serious (p=0·31), including one patient who died in the second washout period.

INTERPRETATION

RUSF providing 500 kcal/day results in small weight gains in children with sickle-cell disease. However, even without arginine and citrulline fortification, RUSF seems to ameliorate arginine dysregulation and might improve endothelial function. Long-term studies are required to assess whether these physiological effects translate to improved clinical outcomes and better growth and development in patients with sickle-cell disease.

FUNDING

Wellcome Trust.

Association between atherosclerosis and handgrip strength in non-hypertensive populations in India and Japan

Aim

Although several risk factors contribute to the development of sarcopenia, whether preclinical atherosclerosis contributes to the risk of sarcopenia is not established. The present cross‐sectional study aimed to investigate if there is an association between preclinical atherosclerosis and muscle strength among two ethnic populations.

Methods

Participants included individuals aged ≥40 years and enrolled in the third follow‐up examination of the Andhra Pradesh Children and Parents Study, India, and in the baseline assessments of the Nagasaki Islands Study, Japan. Preclinical atherosclerosis was evaluated by carotid intima‐media thickness, brachial‐ankle pulse wave velocity, cardio‐ankle vascular index. The association of carotid intima‐media thickness and pulse wave velocity/cardio‐ankle vascular index with handgrip strength (HGS) was analyzed separately in the sexes and for hypertensive status from the two cohorts using a multivariable linear regression model.

Results

Data on a total of 1501 participants in India and 3136 participants in Japan were analyzed. Carotid intima‐media thickness was negatively associated with HGS in non‐hypertensive Indian men (B coefficient = −5.38, P = 0.036). Arterial stiffness was also associated with HGS in non‐hypertensive Indian men (B = −0.97, P = 0.001), but not in hypertensive Indian men. Same as Indian men, we found the significant associations between arterial stiffness and HGS in non‐hypertensive women in both India and Japan (B = −0.44, P = 0.020, B = −0.63, P = 0.016, respectively), but not in hypertensive women.

Conclusions

The negative association between preclinical atherosclerosis and HGS was dominantly found in non‐hypertensive participants. Geriatr Gerontol Int 2018; 18: 1071–1078.

A pilot study of a non-invasive oral nitrate stable isotopic method suggests that arginine and citrulline supplementation increases whole-body NO production in Tanzanian children with sickle cell disease

Background

Low bioavailability of nitric oxide (NO) is implicated in the pathophysiology of sickle cell disease (SCD). We designed a nested pilot study to be conducted within a clinical trial testing the effects of a daily ready-to-use supplementary food (RUSF) fortified with arginine (Arg) and citrulline (Citr) vs. non-fortified RUSF in children with SCD. The pilot study evaluated 1) the feasibility of a non-invasive stable isotope method to measure whole-body NO production and 2) whether Arg+Citr supplementation was associated with increased whole-body NO production.

Subjects

Twenty-nine children (70% male, 9–11years, weight 16.3–31.3 kg) with SCD.

Methods

Sixteen children received RUSF+Arg/Citr (Arg, 0.2  g/kg/day; Citr, 0.1  g/kg/day) in combination with daily chloroquine (50 mg) and thirteen received the base RUSF in combination with weekly chloroquine (150 mg). Plasma amino acids were assessed using ion-exchange elution (Biochrom-30, Biochrom, UK) and whole-body NO production was measured using a non-invasive stable isotopic method.

Results

The RUSF+Arg/Citr intervention increased plasma arginine (P = .02) and ornithine (P = .003) and decreased the ratio of asymmetric dimethylarginine to arginine (P = .01), compared to the base RUSF. A significant increase in whole-body NO production was observed in the RUSF-Arg/Citr group compared to baseline (weight-adjusted systemic NO synthesis 3.38 ± 2.29 μmol/kg/hr vs 2.35 ± 1.13 μmol/kg/hr, P = .04). No significant changes were detected in the base RUSF group (weight-adjusted systemic NO synthesis 2.64 ± 1.14 μmol/kg/hr vs 2.53 ± 1.12 μmol/kg/hr, P = .80).

Conclusions

The non-invasive stable isotopic method was acceptable and the results provided supporting evidence that Arg/Citr supplementation may increase systemic NO synthesis in children with SCD.

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This method for measuring whole-body NO synthesis is feasible in young children.

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The isotopic decay of the stable isotope tracer demonstrated good linear fit.

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Arginine and citrulline supplementation may increase whole-body NO synthesis.

Fetal Hemoglobin is Associated with Peripheral Oxygen Saturation in Sickle Cell Disease in Tanzania

Fetal hemoglobin (HbF) and peripheral hemoglobin oxygen saturation (SpO₂) both predict clinical severity in sickle cell disease (SCD), while reticulocytosis is associated with vasculopathy, but there are few data on mechanisms. HbF, SpO₂ and routine clinical and laboratory measures were available in a Tanzanian cohort of 1175 SCD individuals aged ≥ 5 years and the association with SpO₂ (as response variable transformed to a Poisson distribution) was assessed by negative binomial model with age and sex as covariates. Increase in HbF was associated with increased SpO₂ (rate ratio, RR = 1.19; 95% confidence intervals [CI] 1.04, 1.37 per natural log unit of HbF; p = 0.0004). In univariable analysis, SpO₂ was inversely associated with age, reticulocyte count, and log (total bilirubin) and directly with pulse, SBP, hemoglobin, and log(HbF). In multivariable regression log(HbF) (RR 1.191; 95%CI 1.04, 1.37; p = 0.013), pulse (RR 1.01; 95%CI 1.00, 1.01; p = 0.026), SBP (RR 1.008; 95%CI 1.00, 1.02; p = 0.014), and hemoglobin (1.120; 95%CI 1.05, 1.19; p = 0.001) were positively and independently associated with SpO₂ while reticulocyte count (RR 0.985; 95%CI 0.97, 0.99; p = 0.019) was independently inversely associated with SpO₂. In SCD, improving SpO₂, in part through cardiovascular compensation and associated with reduced reticulocytosis, may be a mechanism by which HbF reduces disease severity.

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Fetal hemoglobin may moderate sickle cell disease through increased oxygen saturation.

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Low oxygen saturation is associated with reticulocytosis which might moderate cerebral vasculopathy and stroke risk.

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Higher pulse rate and systolic blood pressure in those with higher SpO₂ suggests cardiovascular compensation for low SpO_2.

Fetal hemoglobin (HbF) is normally synthesized during intrauterine life and it starts to decline before birth being replaced by adult hemoglobin (HbA). However some individuals continue to synthesize HbF to adulthood and are relatively protected from severe sickle cell disease. The mechanism of HbF protection in SCD has not been entirely established. This study reports a positive association between HbF and oxygen saturation (SpO₂). Higher SpO₂ is associated with decreased reticulocytes but increased pulse rate and systolic blood pressure, suggesting SpO₂ is maintained in part through cardiovascular compensation. Increasing HbF may reduce disease severity partly through increasing SpO_2.

Population-Based Incidence Rates of First-Ever Stroke in Central Vietnam

Introduction

Stroke incidence data with methodologically acceptable design in Southeast Asia countries is limited. This study aimed to determine incidence of age-, sex- and subtype-specific first-ever stroke (FES) in Vietnam.

Methods

We conducted a hospital-based retrospective study, targeting all stroke cases hospitalized at a solo-provider hospital in our study site of Nha Trang from January 2009 to December 2011 with International Classification of Diseases, 10th revision (ICD-10) codes I60-69. We calculated positive predictive values (PPVs) of each ICD-10-coded stroke by conducting a detailed case review of 190 randomly selected admissions with ICD-10 codes of I60-I69. These PPVs were then used to estimate annual incident stroke cases from the computerized database. National census data in 2009 was used as a denominator.

Results

2,693 eligible admissions were recorded during the study period. The crude annual incidence rate of total FES was 90.2 per 100,000 population (95% CI 81.1–100.2). The age-adjusted incidence of FES was 115.7 (95% CI 95.9–139.1) when adjusted to the WHO world populations. Importantly, age-adjusted intracerebral hemorrhage was as much as one third of total FES: 36.9 (95% CI 26.1–51.0).

Conclusions

We found a considerable proportion of FES in Vietnam to be attributable to intracerebral hemorrhage, which is as high or exceeding levels seen in high-income countries. A high prevalence of improperly treated hypertension in Vietnam may underlie the high prevalence of intracerebral hemorrhagic stroke in this population.

Nocturnal haemoglobin oxygen desaturation in urban and rural East African paediatric cohorts with and without sickle cell anaemia: a cross-sectional study

Low haemoglobin oxygen saturation (SpO2) predicts complications in children with sickle cell anaemia (SCA) in the North but there are few data from Africa, where the majority of the patients reside. We measured daytime and overnight SpO2 in children with SCA in routine follow-up clinic, and controls without symptoms of SCA, comparing rural (Kilifi, Kenya) and urban (Dar-es-Salaam, Tanzania) cohorts. Daytime SpO2 was lower in 65 Tanzanian children with SCA (TS; median 97 (IQR 94-100)%); p<0.0001) than in 113 Kenyan children with SCA (KS; 99 (98-100)%) and 20 Tanzanian controls (TC; 100 (98-100)%). Compared with 95 Kenyan children with SCA, in 54 Tanzanian children with SCA and 19 TC who returned for overnight oximetry, mean (KS 99.0 (96.7-99.8)%; TS 97.9 (95.4-99.3)%; TC 98.4 (97.5-99.1)%; p=0.01) and minimum nocturnal SpO2 (92 (86-95)%; 87 (78.5-91)%; 90 (83.5-93)% p=0.0001) were lower. The difference between children with SCA persisted after adjustment for haemoglobin (p=0.004). Urban Tanzanian children, with and without SCA, experience greater exposure to low daytime and night-time SpO2 compared with rural Kenyan children with SCA. Possible explanations include differences in the prevalence of obstructive sleep apnoea or asthma, alterations in the oxyhaemoglobin desaturation curve or cardiovascular compromise, for example, to shunting at atrial or pulmonary level secondary to increased pulmonary artery pressure. The fact that non-SCA siblings in the urban area are also affected suggests that environmental exposures, for example, air pollution, nutrition or physical exercise, may play a role. Further studies should determine aetiology and clinical relevance for the SCA phenotype in children resident in Africa.

Effect of Daily Antenatal Iron Supplementation on Plasmodium Infection in Kenyan Women: A Randomized Clinical Trial

IMPORTANCE

Anemia affects most pregnant African women and is predominantly due to iron deficiency, but antenatal iron supplementation has uncertain health benefits and can increase the malaria burden.

OBJECTIVE

To measure the effect of antenatal iron supplementation on maternal Plasmodium infection risk, maternal iron status, and neonatal outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Randomized placebo-controlled trial conducted October 2011 through April 2013 in a malaria endemic area among 470 rural Kenyan women aged 15 to 45 years with singleton pregnancies, gestational age of 13 to 23 weeks, and hemoglobin concentration of 9 g/dL or greater. All women received 5.7 mg iron/day through flour fortification during intervention, and usual intermittent preventive treatment against malaria was given.

INTERVENTIONS

Supervised daily supplementation with 60 mg of elemental iron (as ferrous fumarate, n = 237 women) or placebo (n = 233) from randomization until 1 month postpartum.

MAIN OUTCOMES AND MEASURES

Primary outcome was maternal Plasmodium infection at birth. Predefined secondary outcomes were birth weight and gestational age at delivery, intrauterine growth, and maternal and infant iron status at 1 month after birth.

RESULTS

Among the 470 participating women, 40 women (22 iron, 18 placebo) were lost to follow-up or excluded at birth; 12 mothers were lost to follow-up postpartum (5 iron, 7 placebo). At baseline, 190 of 318 women (59.7%) were iron-deficient. In intention-to-treat analysis, comparison of women who received iron vs placebo, respectively, yielded the following results at birth: Plasmodium infection risk: 50.9% vs 52.1% (crude difference, -1.2%, 95% CI, -11.8% to 9.5%; P = .83); birth weight: 3202 g vs 3053 g (crude difference, 150 g, 95% CI, 56 to 244; P = .002); birth-weight-for-gestational-age z score: 0.52 vs 0.31 (crude difference, 0.21, 95% CI, -0.11 to 0.52; P = .20); and at 1 month after birth: maternal hemoglobin concentration: 12.89 g/dL vs 11.99 g/dL (crude difference, 0.90 g/dL, 95% CI, 0.61 to 1.19; P < .001); geometric mean maternal plasma ferritin concentration: 32.1 µg/L vs 14.4 µg/L (crude difference, 123.4%, 95% CI, 85.5% to 169.1%; P < .001); geometric mean neonatal plasma ferritin concentration: 163.0 µg/L vs 138.7 µg/L (crude difference, 17.5%, 95% CI, 2.4% to 34.8%; P = .02). Serious adverse events were reported for 9 and 12 women who received iron and placebo, respectively. There was no evidence that intervention effects on Plasmodium infection risk were modified by intermittent preventive treatment use.

CONCLUSIONS AND RELEVANCE

Among rural Kenyan women with singleton pregnancies, administration of daily iron supplementation, compared with administration of placebo, resulted in no significant differences in overall maternal Plasmodium infection risk. Iron supplementation led to increased birth weight.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01308112.

Bacteraemia in sickle cell anaemia is associated with low haemoglobin: a report of 890 admissions to a tertiary hospital in Tanzania

Bacteraemia is a leading cause of morbidity in sickle cell anaemia (SCA), but information from studies in Africa is limited. We evaluated 890 admissions from 648 SCA patients at a tertiary hospital in Tanzania. Bacteraemia was present in 43 admissions (4·8%); isolates included Staphylococcus aureus (12/43; 28%), non‐Typhi Salmonella (9/43; 21%), Streptococcus pneumoniae (3/43; 7%) and Salmonella Typhi (2/43; 5%). Compared to SCA patients without bacteraemia, SCA patients with bacteraemia had significantly lower haemoglobin [71 g/l vs. 62 g/l, odds ratio 0·72 (95% confidence interval 0·56–0·91), P < 0·01]. Further exploration is needed of the relationship between anaemia and bacterial infections in SCA in Africa.

Negative Epistasis between Sickle and Foetal Haemoglobin Suggests a Reduction in Protection against Malaria

BACKGROUND

Haemoglobin variants, Sickle (HbS) and foetal (HbF) have been associated with malaria protection. This study explores epistatic interactions between HbS and HbF on malaria infection.

METHODS

The study was conducted between March 2004 and December 2013 within the sickle cell disease (SCD) programme at Muhimbili National Hospital, Tanzania. SCD status was categorized into HbAA, HbAS and HbSS using hemoglobin electrophoresis and High Performance Liquid Chromatography (HPLC). HbF levels were determined by HPLC. Malaria was diagnosed using rapid diagnostic test and/or blood film. Logistic regression and generalized estimating equations models were used to evaluate associations between SCD status, HbF and malaria.

FINDINGS

2,049 individuals with age range 0-70 years, HbAA 311(15.2%), HbAS 241(11.8%) and HbSS 1,497(73.1%) were analysed. At enrolment, malaria prevalence was significantly higher in HbAA 13.2% compared to HbAS 1.24% and HbSS 1.34% (p<0.001). Mean HbF was lower in those with malaria compared to those without malaria in HbAA (0.43% vs 0.82%) but was the reverse in HbSS (8.10% vs 5.59%). An increase in HbF was associated with a decrease in risk of malaria OR=0.50 (95%CI: 0.28, 0.90; p=0.021) in HbAA, whereas for HbSS the risk of malaria increased OR=2.94 (1.44, 5.98; p=0.003). A similar pattern was seen during multiple visits; HbAA OR=0.52 (0.34, 0.80; p=0.003) vs HbSS OR=2.01 (1.27, 3.23; p=0.003).

CONCLUSION

Higher prevalence of malaria in HbAA compared to HbAS and HbSS confirmed the protective effect of HbS. Lower prevalence of malaria in HbAA with high HbF supports a protective effect of HbF. However, in HbSS, the higher prevalence of malaria with high levels of HbF suggests loss of malaria protection. This is the first epidemiological study to suggest a negative epistasis between HbF and HbS on malaria.

Genetic association of fetal-hemoglobin levels in individuals with sickle cell disease in Tanzania maps to conserved regulatory elements within the MYB core enhancer

BACKGROUND

Common genetic variants residing near upstream regulatory elements for MYB, the gene encoding transcription factor cMYB, promote the persistence of fetal hemoglobin (HbF) into adulthood. While they have no consequences in healthy individuals, high HbF levels have major clinical benefits in patients with sickle cell disease (SCD) or β thalassemia. Here, we present our detailed investigation of HBS1L-MYB intergenic polymorphism block 2 (HMIP-2), the central component of the complex quantitative-trait locus upstream of MYB, in 1,022 individuals with SCD in Tanzania.

METHODS

We have looked at 1022 individuals with HbSS or HbS/β(0) in Tanzania. In order to achieve a detailed analysis of HMIP-2, we performed targeted genotyping for a total of 10 SNPs and extracted additional 528 SNPs information from a genome wide scan involving the same population. Using MACH, we utilized the existing YRI data from 1000 genomes to impute 54 SNPs situated within HIMP-2.

RESULTS

Seven HbF-increasing, low-frequency variants (β > 0.3, p < 10(-5), f ≤ 0.05) were located in two partially-independent sub-loci, HMIP-2A and HMIP-2B. The spectrum of haplotypes carrying such alleles was diverse when compared to European and West African reference populations: we detected one such haplotype at sub-locus HMIP-2A, two at HMIP-2B, and a fourth including high-HbF alleles at both sub-loci ('Eurasian' haplotype clade). In the region of HMIP-2A a putative functional variant (a 3-bp indel) has been described previously, but no such candidate causative variant exists at HMIP-2B. Extending our dataset through imputation with 1000 Genomes, whole-genome-sequence data, we have mapped peak association at HMIP-2B to an 11-kb region around rs9494145 and rs9483788, flanked by two conserved regulatory elements for MYB.

CONCLUSIONS

Studies in populations from the African continent provide distinct opportunities for mapping disease-modifying genetic loci, especially for conditions that are highly prevalent there, such as SCD. Population-genetic characteristics of our cohort, such as ethnic diversity and the predominance of shorter, African-type haplotypes, can add to the power of such studies.

Left ventricular rotational mechanics in Tanzanian children with sickle cell disease

Background

Sickle cell disease (SCD) is a common inherited hemoglobinopathy. Adults with SCD manifest both systolic and diastolic cardiac dysfunction, though the age of onset of dysfunction has not been defined. Left ventricular (LV) rotational mechanics have not been studied in children with SCD. The aim of this study was to investigate whether cardiac rotational mechanics differed between children with SCD and age-matched controls.

Methods

Basal and apical LV short-axis images were acquired prospectively in 213 patients with SCD (mean age, 14.1 ± 2.6 years) and 49 controls (mean age, 13.3 ± 2.8 years) from the Muhimbili Sickle Cohort in Dar es Salaam, Tanzania. The magnitude of basal and apical rotation, net twist angle, torsion, and untwist rate were obtained by two-dimensional speckle-tracking. The timing of events was normalized to aortic valve closure.

Results

Mean basal rotation was significantly lower in patients with SCD compared with controls (P = .012), although no difference was observed in apical rotation (P = .37). No statistically significant differences in torsion or net twist angle were detected. Rotation rate at the apex (P = .001) and base (P = .0004) were significantly slower in subjects with SCD compared with controls. Mean peak untwisting rate was also significantly slower in patients with SCD (P = .006). No associations were found between hemoglobin concentration and apical rotation, basal rotation, net twist, and torsion.

Conclusion

This study demonstrates alterations in LV rotational mechanics in children with SCD, including lower basal rotation, peak differential twist, and untwist rate. These abnormalities denote subclinical changes in LV systolic and diastolic performance in children with SCD. Future work may reveal an association between rotational metrics and long-term patient outcomes.

Genetic variants at HbF-modifier loci moderate anemia and leukocytosis in sickle cell disease in Tanzania

Fetal hemoglobin (HbF) is a recognized modulator of sickle cell disease (SCD) severity. HbF levels are strongly influenced by genetic variants at three major genetic loci, Xmn1‐HBG2, HMIP‐2, and BCL11A, but the effect of these loci on the hematological phenotype in SCD, has so far not been investigated. In a cohort of individuals with SCD in Tanzania (HbSS and HbS/β° thalassemia, n = 726, aged 5 or older), HbF levels were positively correlated with hemoglobin, red blood cell (RBC) indices, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH), and negatively with white blood cell (WBC) and platelet counts (all P < 0.0001). We subsequently assessed the contribution of the three HbF modifier loci and detected diverse effects, including a reduction in anemia, leukocytosis, and thrombocytosis associated with certain HbF‐promoting alleles. The presence of the ‘T’ allele at Xmn1‐HBG2 led to a significant increase in hemoglobin (P = 9.8 × 10⁻³) but no changes in cellular hemoglobin content. Xmn1‐HBG2 ‘T’ also has a weak effect decreasing WBC (P = 0.06) and platelet (P = 0.06) counts. The BCL11A variant (rs11886868‐‘C’) increases hemoglobin (P = 2 × 10⁻³) and one of the HBS1L‐MYB variants decreases WBC values selectively (P = 2.3 × 10⁻⁴). The distinct pattern of effects of each variant suggests that both, disease alleviation through increased HbF production, and ‘pleiotropic’ effects on blood cells, are involved, affecting a variety of pathways. Am. J. Hematol. 90:E1–E4, 2015. © 2014 Wiley Periodicals, Inc.

Health policy for sickle cell disease in Africa: experience from Tanzania on interventions to reduce under-five mortality

Tanzania has made considerable progress towards reducing childhood mortality, achieving a 57% decrease between 1980 and 2011. This epidemiological transition will cause a reduction in the contribution of infectious diseases to childhood mortality and increase in contribution from noncommunicable diseases (NCDs). Haemoglobinopathies are amongst the most common childhood NCDs, with sickle cell disease (SCD) being the commonest haemoglobinopathy in Africa. In Tanzania, 10 313 children with SCD under 5 years of age (U5) are estimated to die every year, contributing an estimated 7% of overall deaths in U5 children. Key policies that governments in Africa are able to implement would reduce mortality in SCD, focusing on newborn screening and comprehensive SCD care programmes. Such programmes would ensure that interventions such as prevention of infections using penicillin plus prompt diagnosis and treatment of complications are provided to all individuals with SCD.

Genome wide association study of fetal hemoglobin in sickle cell anemia in Tanzania

Background

Fetal hemoglobin (HbF) is an important modulator of sickle cell disease (SCD). HbF has previously been shown to be affected by variants at three loci on chromosomes 2, 6 and 11, but it is likely that additional loci remain to be discovered.

Methods and Findings

We conducted a genome-wide association study (GWAS) in 1,213 SCA (HbSS/HbSβ⁰) patients in Tanzania. Genotyping was done with Illumina Omni2.5 array and imputation using 1000 Genomes Phase I release data. Association with HbF was analysed using a linear mixed model to control for complex population structure within our study. We successfully replicated known associations for HbF near BCL11A and the HBS1L-MYB intergenic polymorphisms (HMIP), including multiple independent effects near BCL11A, consistent with previous reports. We observed eight additional associations with P<10⁻⁶. These associations could not be replicated in a SCA population in the UK.

Conclusions

This is the largest GWAS study in SCA in Africa. We have confirmed known associations and identified new genetic associations with HbF that require further replication in SCA populations in Africa.

Maternal nutrition at conception modulates DNA methylation of human metastable epialleles

In experimental animals, maternal diet during the periconceptional period influences the establishment of DNA methylation at metastable epialleles in the offspring, with permanent phenotypic consequences. Pronounced naturally occurring seasonal differences in the diet of rural Gambian women allowed us to test this in humans. We show that significant seasonal variations in methyl-donor nutrient intake of mothers around the time of conception influence 13 relevant plasma biomarkers. The level of several of these maternal biomarkers predicts increased/decreased methylation at metastable epialleles in DNA extracted from lymphocytes and hair follicles in infants postnatally. Our results demonstrate that maternal nutritional status during early pregnancy causes persistent and systemic epigenetic changes at human metastable epialleles.

Haptoglobin, alpha-thalassaemia and glucose-6-phosphate dehydrogenase polymorphisms and risk of abnormal transcranial Doppler among patients with sickle cell anaemia in Tanzania

Transcranial Doppler ultrasonography measures cerebral blood flow velocity (CBFv) of basal intracranial vessels and is used clinically to detect stroke risk in children with sickle cell anaemia (SCA). Co‐inheritance in SCA of alpha‐thalassaemia and glucose‐6‐phosphate dehydrogenase (G6PD) polymorphisms is reported to associate with high CBFv and/or risk of stroke. The effect of a common functional polymorphism of haptoglobin (HP) is unknown. We investigated the effect of co‐inheritance of these polymorphisms on CBFv in 601 stroke‐free Tanzanian SCA patients aged <24 years. Homozygosity for alpha‐thalassaemia 3·7 deletion was significantly associated with reduced mean CBFv compared to wild‐type (β‐coefficient −16·1 cm/s, P = 0·002) adjusted for age and survey year. Inheritance of 1 or 2 alpha‐thalassaemia deletions was associated with decreased risk of abnormally high CBFv, compared to published data from Kenyan healthy control children (Relative risk ratio [RRR] = 0·53 [95% confidence interval (CI):0·35–0·8] & RRR = 0·43 [95% CI:0·23–0·78]), and reduced risk of abnormally low CBFv for 1 deletion only (RRR = 0·38 [95% CI:0·17–0·83]). No effects were observed for G6PD or HP polymorphisms. This is the first report of the effects of co‐inheritance of common polymorphisms, including the HP polymorphism, on CBFv in SCA patients resident in Africa and confirms the importance of alpha‐thalassaemia in reducing risk of abnormal CBFv.

DNA methylation potential: dietary intake and blood concentrations of one-carbon metabolites and cofactors in rural African women

BACKGROUND

Animal models show that periconceptional supplementation with folic acid, vitamin B-12, choline, and betaine can induce differences in offspring phenotype mediated by epigenetic changes in DNA. In humans, altered DNA methylation patterns have been observed in offspring whose mothers were exposed to famine or who conceived in the Gambian rainy season.

OBJECTIVE

The objective was to understand the seasonality of DNA methylation patterns in rural Gambian women. We studied natural variations in dietary intake of nutrients involved in methyl-donor pathways and their effect on the respective metabolic biomarkers.

DESIGN

In 30 women of reproductive age (18-45 y), we monitored diets monthly for 1 y by using 48-h weighed records to measure intakes of choline, betaine, folate, methionine, riboflavin, and vitamins B-6 and B-12. Blood biomarkers of these nutrients, S-adenosylhomocysteine (SAH), S-adenosylmethionine (SAM), homocysteine, cysteine, and dimethylglycine were also assessed monthly.

RESULTS

Dietary intakes of riboflavin, folate, choline, and betaine varied significantly by season; the most dramatic variation was seen for betaine. All metabolic biomarkers showed significant seasonality, and vitamin B-6 and folate had the highest fluctuations. Correlations between dietary intakes and blood biomarkers were found for riboflavin, vitamin B-6, active vitamin B-12 (holotranscobalamin), and betaine. We observed a seasonal switch between the betaine and folate pathways and a probable limiting role of riboflavin in these processes and a higher SAM/SAH ratio during the rainy season.

CONCLUSIONS

Naturally occurring seasonal variations in food-consumption patterns have a profound effect on methyl-donor biomarker status. The direction of these changes was consistent with previously reported differences in methylation of metastable epialleles. This trial was registered at www.clinicaltrials.gov as NCT01811641.

Randomised controlled trial of weekly chloroquine to re-establish normal erythron iron flux and haemoglobin recovery in postmalarial anaemia

OBJECTIVE

To determine if low-dose weekly chloroquine (CQ) therapy improves recovery from malaria-associated anaemia.

DESIGN

Proof of concept randomised clinical trial.

SETTING

West Kiang District, Lower River Region, The Gambia.

PARTICIPANTS

Children resident in participating communities, aged 12-72 months, with uncomplicated malaria identified using active case detection over two consecutive malaria transmission seasons.

INTERVENTIONS

In 2007, eligible children were randomised to chloroquine-sulfadoxine/pyrimethamine (CQ-SP) or co-artemether (ACT) antimalarial therapy, and after parasite clearance on day 3 were subsequently re-randomised (double-blind) to weekly low-dose CQ (5 mg/kg) or placebo. In 2008, all eligible children were treated with ACT and subsequently randomised to CQ or placebo.

OUTCOME MEASURES

The primary outcome was a change in haemoglobin from baseline (day 3 of antimalarial treatment) to day 90 in the CQ and placebo treatment arms. Secondary outcomes were changes in urinary neopterin as a marker of macrophage activation, markers of erythropoietic response and prevalence of submicroscopic parasitaemia. Change in haemoglobin in the placebo arm by initial antimalarial treatment was also assessed.

RESULTS

In 2007, 101 children with uncomplicated malaria were randomised to antimalarial treatment with CQ-SP or ACT and 65 were subsequently randomised to weekly CQ or placebo. In 2008, all children received ACT antimalarial treatment and 31 were subsequently randomised to receive weekly CQ or placebo. Follow-up to day 90 was 96%. There was no effect of weekly CQ vs placebo on change in haemoglobin at day 90 (CQ+10.04 g/L (95% CI 6.66 to 13.42) vs placebo +7.61 g/L (95% CI 2.88 to 12.35)). There was no effect on the secondary outcomes assessed, or effect of initial antimalarial therapy on haemoglobin recovery. Higher day 90 haemoglobin correlated independently with older age, not being stunted, higher haemoglobin at day 0 and adequate iron status at day 3.

CONCLUSIONS

Weekly low-dose CQ after effective antimalarial treatment is not effective in improving recovery from postmalarial anaemia.

TRIAL REGISTRATION

The clinical trial registration number is NCT00473837 (ClinicalTrials.gov).

Sickle cell anemia: iron availability and nocturnal oximetry

STUDY OBJECTIVE

To test the hypothesis that low iron availability, measured as transferrin saturation, is associated with low nocturnal hemoglobin oxygen saturation (SpO(2)) in children with homozygous sickle cell anemia (SCA; hemoglobin SS).

METHODS

This was a cross-sectional study of Tanzanian children with SCA who were not receiving regular blood transfusions. Thirty-two children (16 boys) with SCA (mean age 8.0, range 3.6-15.3 years) underwent motion-resistant nocturnal oximetry (Masimo Radical) and had steady state serum transferrin saturation and hematological indices assessed.

RESULTS

Higher transferrin saturation, adjusted for age and α-thalassemia deletion, was associated with lower nocturnal mean SpO(2) (p = 0.013, r(2) = 0.41), number of SpO(2) dips/h > 3% from baseline (p = 0.008, r(2) = 0.19) and with min/h with SpO(2) < 90% (p = 0.026 r(2) = 0.16). Transferrin saturation < 16% (indicative of iron deficiency) was associated with a 2.2% higher nocturnal mean SpO(2).

CONCLUSIONS

Contrary to our hypothesis, higher iron availability, assessed by transferrin saturation, is associated with nocturnal chronic and intermittent hemoglobin oxygen desaturation in SCA. Whether these associations are causal and are driven by hypoxia-inducible factor and hepcidin-mediated upregulation of demand for iron warrants further investigation.

Iron and malaria interactions: research needs from basic science to global policy

The resurgence in interest and concern regarding the potentially malign interactions between iron administration and malaria infections, especially in young children and pregnant women, has generated a research agenda that is both broad and deep. This paper highlights some of the key questions under 5 headings: basic science; clinical science and epidemiology; technological developments; country level planning; and global policy. At a time of unparalleled progress in basic science, which is illuminating the mechanisms by which iron interacts with infectious organisms, it is concluded that there are good medium-term prospects for achieving policy breakthroughs based on a secure foundation of disease-nutrient interactions. However, it is also stressed that there is much that can be done in the interim, especially in relation to health systems and implementation research that can empower systems to integrate iron interventions with programs for malaria prevention, surveillance, and treatment.

Peripheral vascular response to inspiratory breath hold in paediatric homozygous sickle cell disease

New Findings

• What is the central question of this study?

Autonomic nervous dysfunction is implicated in complications of sickle cell anaemia (SCA). In healthy adults, a deep inspiratory breath hold (IBH) elicits rapid transient SNS- mediated vasoconstriction detectable using Laser Doppler Flux (LDF) assessment of the finger-tip cutaneous micovasculature.

• What is the main finding and its importance?

We demonstrate significantly increased resting peripheral blood flow and sympathetic activity in African children with SCA compared to sibling controls and increased sympathetic stimulation in response to vasoprovocation with DIG.

This study is the first to observe an inverse association between resting peripheral blood flow and haemoglobin oxygen saturation (SpO2). These phenomena may be an adaptive response to the hypoxic exposure in SCA.

There is increasing evidence that autonomic dysfunction in adults with homozygous sickle cell (haemoglobin SS) disease is associated with enhanced autonomic nervous system-mediated control of microvascular perfusion. However, it is unclear whether such differences are detectable in children with SS disease. We studied 65 children with SS disease [38 boys; median age 7.2 (interquartile range 5.1–10.6) years] and 20 control children without symptoms of SS disease [8 boys; 8.7 (5.5–10.8) years] and recorded mean arterial blood pressure (ABP) and daytime haemoglobin oxygen saturation (). Cutaneous blood flux at rest (RBF) and during the sympathetically activated vasoconstrictor response to inspiratory breath hold (IBH) were measured in the finger pulp of the non-dominant hand using laser Doppler fluximetry. Local factors mediating flow motion were assessed by power spectral density analysis of the oscillatory components of the laser Doppler signal. The RBF measured across the two study groups was negatively associated with age (r=−0.25, P < 0.0001), ABP (r=−0.27, P= 0.02) and daytime (r=−0.30, P= 0.005). Children with SS disease had a higher RBF (P= 0.005) and enhanced vasoconstrictor response to IBH (P= 0.002) compared with control children. In children with SS disease, higher RBF was associated with an increase in the sympathetic interval (r=−0.28, P= 0.022). The SS disease status, daytime and age explained 22% of the variance in vasoconstrictor response to IBH (P < 0.0001). Our findings suggest that blood flow and blood flow responses in the skin of young African children with SS disease differ from those of healthy control children, with increased resting peripheral blood flow and increased sympathetic stimulation from a young age in SS disease. They further suggest that the laser Doppler flowmetry technique with inspiratory breath hold manoeuvre appears to be robust for use in young children with SS disease, to explore interactions between , ABP and autonomic function with clinical complications, e.g. skin ulceration.

Low folate status and indoor pollution are risk factors for endemic optic neuropathy in Tanzania

AIMS

Bilateral optic neuropathy in Dar-es-Salaam, Tanzania was first reported as an epidemic in 1988. Now argued to be endemic in 2010, the aetiology remains unclear. The authors investigated the hypothesis that low folate and vitamin B₁₂ status are associated with optic neuropathy, and also sought to investigate whether mercury, commonly used drugs, dietary factors and indoor pollution may also be risk factors.

METHODS

57 cases and 102 controls were recruited from two tertiary referral centres in Dar-es-Salaam. Data were collected on demographic characteristics, diet, medication history and HIV status. Folate and vitamin B₁₂ (holo-transcobalamin) were measured in stored serum samples. Exposure to mercury was assessed from concentrations in random urine samples.

RESULTS

Cooking indoors more than twice per week (OR 54.48 (95% CI 9.30 to 319.10)) and indoor use of charcoal or firewood (OR 21.20 (95% CI 2.51 to 179.36)) increased the risk of optic neuropathy. Risk was reduced in those with a higher folate status (highest versus lowest quartile OR=0.11 (95% CI 0.02 to 0.51)) and higher protein intakes (OR=0.84 (95% CI 0.72 to 0.96). No association was found with mercury exposure or any common drug or food commodity.

CONCLUSION

This study presents the first direct evidence of low folate status and indoor pollution in the aetiology of endemic bilateral optic neuropathy in Tanzania.