Inappropriately low glycated hemoglobin values and hemolysis in HIV-infected patients

What Is the Influence of HIV Serostatus on HbA1c? A Prospective Analysis Using Continuous Glucose Monitoring

OBJECTIVE

Type 2 diabetes (T2D) is reported to be more common in people living with HIV (PLWH). Clinical guidelines recommend screening for diabetes in PLWH, but there is no agreed method due to studies reporting HbA1c is falsely low in PLWH. These studies were performed in the early HIV era when participants were taking older preparations of antiretroviral therapy that are rarely used today. We aimed to investigate whether HIV serostatus influences HbA1c.

RESEARCH DESIGNS AND METHODS

We conducted a prospective cohort study of PLWH and age- and sex-matched HIV-negative participants who were purposely recruited from clinics in Brighton, U.K. Each participant wore a Dexcom G6 continuous glucose monitor (CGM) for up to 10 days, had glucose measured during an oral glucose tolerance test, and fructosamine and paired HbA1c were measured. We performed regression analysis to assess the influence of HIV on HbA1c and used a separate model for CGM glucose, venous glucose, and fructosamine. In addition, we included predictor variables used in previous studies that explored HbA1c discrepancy.

RESULTS

We recruited 60 PLWH (90% men, 50% with T2D, mean ± SD age 57 ± 10.7 years, 100% undetectable viral load) and 48 people without HIV (92% men, 30% with T2D, mean age 57.7 ± 8.9 years). We found that HIV serostatus did not have a significant influence on HbA1c within the regression models.

CONCLUSIONS

We performed a comprehensive assessment of glycemia to assess whether HIV serostatus influences HbA1c. We did not find any strong evidence that HIV serostatus influenced HbA1c. The results of our study support incorporating HbA1c into routine clinical blood work in PLWH.

HIV and type 2 diabetes: An evolving story

INTRODUCTION

Diabetes is widely reported to be more common in people living with HIV (PLWH). Much of the data supporting this originated during the earlier HIV era. The perceived increased risk of type 2 diabetes is reflected in HIV clinical guidelines that recommend screening for diabetes in PLWH on anti-retroviral therapy (ART). However, international HIV clinical guidelines do not agree on the best marker of glycaemia to screen for diabetes. This stems from studies that suggest HbA1c underestimates glycaemia in PLWH.

METHODS

Within this review we summarise the literature surrounding the association of HIV and type 2 diabetes and how this has changed over time. We also present the evidence on HbA1c discrepancy in PLWH.

CONCLUSION

We suggest there is no basis to any international guidelines to restrict HbA1c based on HIV serostatus. We recommend, using the current evidence, that PLWH should be screened annually for diabetes in keeping with country specific guidance. Finally, we suggest future work to elucidate phenotype and natural history of type 2 diabetes in PLWH across all populations.

The Effect of Iron Replacement Therapy on HbA1c Levels in Diabetic and Nondiabetic Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies have reported that iron-deficiency anemia (IDA) and its treatment might lead to a distorted reading of glycated hemoglobin (HbA1c) value. Hence, this review aims to systematically investigate the effect of iron replacement therapy (IRT) on HbA1c levels, as the literature is deficient in assessing this clinical phenomenon.

METHODS

An electronic search of the Cochrane, MEDLINE, and Embase databases was conducted by four independent authors.

RESULTS

Among the 8332 articles identified using the search strategy, 10 records (with a total of 2113 participants) met the inclusion criteria and were analyzed. In nine of the studies, IRT was found to decrease HbA1c levels; in the remaining study, IRT was found to increase HbA1c levels. The effect size of the pooled standardized mean difference in HbA1c levels between the treatment and control groups with IDA was 1.8 (95% CI = -0.5, 2.31). Heterogeneity was assessed using the I2 and χ2 tests, and the resultant values were 98.46% and p = 0.09, respectively. Additionally, the mean difference between the HbA1c levels (pre-IRT and post-IRT) showed a drop in the HbA1c levels which ranged from 1.20 to 0.43 mg/dL.

CONCLUSIONS

The results suggest that IRT decreases HbA1c levels, and it is helpful in treating IDA patients with poor glycemic control. Accordingly, the results provide an added perspective on antidiabetic medication dosing and physicians' interpretation of initially elevated HbA1c values.

Six-month blood pressure and glucose control among HIV-infected adults with elevated blood pressure and hyperglycemia in northern Tanzania: A prospective observational study

BACKGROUND

People with HIV in sub-Saharan Africa are increasingly developing age-related comorbidities. The purpose of this prospective observational study was to describe 6-month outcomes among Tanzanians with HIV and elevated blood pressure or hyperglycemia under current care pathways.

METHODS

Adults presenting for routine HIV care were enrolled and underwent blood pressure and blood glucose measurements. Participants with abnormal blood pressure or glucose were referred for further care, as per current guidelines. Participants' blood pressure and point-of-care glucose were re-evaluated during their 6-month follow-up visit. Elevated blood pressure was defined as systolic ≥140 mmHg or diastolic ≥90 mmHg. Hyperglycemia was defined as fasting glucose ≥126 mg/dl or random glucose ≥200 mg/dl. An electrocardiogram was obtained at enrollment and at follow-up. Interim myocardial infarction and interim myocardial ischemia were defined as new pathologic Q waves and new T-wave inversions, respectively.

RESULTS

Of 500 participants, 155 had elevated blood pressure and 17 had hyperglycemia at enrolment. At 6-month follow-up, 7 (4.6%) of 155 participants with elevated blood pressure reported current use of an anti-hypertensive medication, 100 (66.2%) had persistent elevated blood pressure, 12 (7.9%) developed interim myocardial infarction, and 13 (8.6%) developed interim myocardial ischemia. Among 17 participants with hyperglycemia, 9 (56%) had persistent hyperglycemia at 6 months and 2 (12.5%) reported current use of an anti-hyperglycemic medication.

CONCLUSIONS

Interventions are needed to improve non-communicable disease care pathways among Tanzanians with HIV.

HIV infection and anaemia do not affect HbA1c for the detection of diabetes in black South Africans: Evidence from the Durban Diabetes Study

OBJECTIVE

South Africa has a high burden of HIV infection and anaemia. These conditions may cause HbA_1c to over- or underestimate glycaemia; however, this has not been comprehensively investigated in African populations. We assessed the association of anaemia, HIV infection and antiretroviral therapy (ART) with HbA_1c , and implications for the detection and diagnosis of diabetes, in a black South African population.

RESEARCH DESIGN AND METHODS

In this population-based cross-sectional study in eThekwini municipality (Durban), South Africa, we assessed HbA_1c and conducted oral glucose tolerance tests (OGTTs), HIV diagnostic tests and full blood count measurements among 1067 participants without a history of diabetes diagnosis. Linear regression was used to examine differences in HbA_1c by anaemia (comparator: no anaemia), or HIV and ART (comparator: no HIV) status. HbA_1c -based diabetes prevalence was compared with OGTT-based prevalence among individuals with anaemia and with untreated and ART-treated HIV.

RESULTS

In adjusted analyses, normocytic and microcytic anaemia were associated with higher HbA_1c compared with no anaemia, whereas macrocytic anaemia and ART-treated HIV were associated with lower HbA_1c compared with no anaemia and no HIV, respectively. However, magnitudes of association were small (range: β  = -3.4 mmol/mol or -0.31%, p < 0.001 [macrocytic anaemia] to β = 2.1 mmol/mol or 0.19%, p < 0.001 [microcytic anaemia]). There was no significant difference in diabetes prevalence based on HbA_1c or OGTT among individuals with anaemia (2.9% vs. 3.3%, p = 0.69), untreated HIV (1.6% vs. 1.6% p = 1.00) or ART-treated HIV (2.9% vs. 1.2%, p = 0.08).

CONCLUSIONS

Our results suggest that anaemia and HIV status appear unlikely to materially affect the utility of HbA_1c for diabetes detection and diagnosis in this population. Further studies are needed to examine these associations in sub-Saharan African populations.

HbA1c Below the Reportable Range

This case report concerns a 71 year old female patient who had a very low glycosylated hemoglobin (HbA1c) despite having a high level of fasting blood glucose. The patient had a decreased erythrocyte count, elevated red blood cell indices, and a reticulocyte count with no evidence of hemoglobinopathy. She reported receiving hydroxychloroquine treatment for systemic lupus erythematosus. Subsequent laboratory investigations revealed hemolysis with formation of cold agglutinin. Because cold agglutinins can interfere with HbA1c assays, the specimens were reanalyzed after warming. The complete blood count results improved, but the HbA1c result did not change. In patients in whom medications and/or medical conditions may interfere with HbA1c levels, alternative measures of glycemic control, such as fructosamine, could be beneficial.

Diagnosis, risk factors and management of diabetes mellitus in HIV-infected persons in France: A real-life setting study

BACKGROUND

Diabetes mellitus (DM) is a major and increasing public health problem that may be underdiagnosed and undertreated among persons living with HIV (PLWH).

OBJECTIVE

To describe the diagnosis, treatment and follow-up of DM among PLWH.

METHODS

This study was performed inside a monocentric cohort of 1494 PLWH. DM was defined as having a FG ≥126 mg/dL twice or a HbA1c ≥6.5%, or a history of diabetes, or receiving antidiabetic treatment. The first visit mentioning a diagnosis of DM was considered as the baseline visit. Chi-Square or Fisher exact test were used to examine the association between categorical variables and DM, Wilcoxon or Student t-test were used for continuous variables.

RESULTS

156 PLWH with DM were included. Compared to non-diabetic participants, they were more likely to be native of Sub Saharan Africa (31.6% vs. 22.4%, p = 0.027) and older (54.6 vs. 49.9 years, p<0.001), to have a higher BMI (> 25 for 46.1% vs. 35.3%, p = 0.020) and a poorer control of HIV (HIV RNA<50 copies/mL: 80.1% vs. 89.5%, p<0.001). The diagnosis of DM was missed in 37.8% of PLWH, and 47.2% of PLWH treated for DM did not reach a HbA1c<7%. PLWH with DM were more frequently on antihypertensive and/or lipid-lowering medications: 94.2% had a LDL-cholesterol <70 mg/dL and 60.9% had a blood pressure <140/90 mmHg.

CONCLUSION

In a setting of HIV-control, HIV care providers should focus on metabolic issues. The management of DM and associated risk factors is mandatory to prevent cardiovascular disease in PLWH.

Diabetes in a TB and HIV-endemic South African population: Analysis of a virtual cohort using routine health data

BACKGROUND

It is widely accepted that people living with diabetes (PLWD) are at increased risk of infectious disease, yet there is a paucity of epidemiology studies on the relationship between diabetes and infectious disease in SSA. In a region with a high burden of infectious disease, this has serious consequences for PLWD.

METHODS AND FINDINGS

Using routinely collected longitudinal health data, we describe the epidemiology of diabetes in a large virtual cohort of PLWD who have a high burden of HIV and TB, from the Khayelitsha subdistrict in the Western Cape Province in South Africa. We described the relationship between previous TB, newly diagnosed TB disease and HIV infection on diabetes using HbA1c results as an outcome measure. The study population was predominately female (67%), 13% had a history of active TB disease and 18% were HIV positive. The HIV positive group had diabetes ascertained at a significantly younger age (46 years c.f. 53 years respectively, p<0.001) and in general had increased HbA1c values over time after their HIV diagnosis, when compared to the HIV-negative group. There was no evidence of TB disease influencing the trajectory of glycaemic control in the long term, but diabetes patients who developed active TB had higher mortality than those without TB (12.4% vs 6.7% p-value < 0.001). HIV and diabetes are both chronic diseases whose long-term management includes drug therapy, however, only 52.8% of the study population with an HIV-diabetes comorbidity had a record of diabetes treatment. In addition, the data suggest overall poor glycaemic control in the study population with only 24.5% of the participants having an HbA1c <7% at baseline despite 85% of the study population being on diabetes treatment.

CONCLUSION

The epidemiologic findings in this exploratory study highlight the need for further research into diabetes outcomes in a high TB and HIV burden setting and demonstrate that routine health data are a valuable resource for understanding disease epidemiology in the general population.

Coronary artery disease in patients with human immunodeficiency virus infection

The life expectancy of people infected with human immunodeficiency virus (HIV) is rising due to better access to combination anti-retroviral therapy (ART). Although ART has reduced acquired immune deficiency syndrome (AIDS) related mortality and morbidity, there has been an increase in non-AIDS defining illnesses such as diabetes mellitus, hypercholesterolemia and coronary artery disease (CAD). HIV is a disease marked by inflammation which has been associated with specific biological vascular processes increasing the risk of premature atherosclerosis. The combination of pre-existing risk factors, atherosclerosis, ART, opportunistic infections and coagulopathy contributes to rising CAD incidence. The prevalence of CAD has emerged as a major contributor of morbidity in these patients due to longer life expectancy. However, ART has been associated with lipodystrophy, dyslipidemia, insulin resistance, diabetes mellitus and CAD. These adverse effects, along with drug-drug interactions when ART is combined with cardiovascular drugs, result in significant challenges in the care of this group of patients. Exercise tolerance testing, echocardiography, myocardial perfusion imaging, coronary computed tomography angiography and magnetic resonance imaging help in the diagnosis of CAD and heart failure and help predict cardiovascular outcomes in a manner similar to non-infected individuals. This review will highlight the pathogenesis and factors that link HIV to CAD, presentation and treatment of HIV-patients presenting with CAD and review briefly the cardiac imaging modalities used to identify this entity and help prognosticate future outcomes.

Primary Care Guidance for Persons With Human Immunodeficiency Virus: 2020 Update by the HIV Medicine Association of the Infectious Diseases Society of America

Advances in antiretroviral therapy (ART) have made it possible for persons with human immunodeficiency virus (HIV) to live a near expected life span, without progressing to AIDS or transmitting HIV to sexual partners or infants. There is, therefore, increasing emphasis on maintaining health throughout the life span. To receive optimal medical care and achieve desired outcomes, persons with HIV must be consistently engaged in care and able to access uninterrupted treatment, including ART. Comprehensive evidence-based HIV primary care guidance is, therefore, more important than ever. Creating a patient-centered, stigma-free care environment is essential for care engagement. Barriers to care must be decreased at the societal, health system, clinic, and individual levels. As the population ages and noncommunicable diseases arise, providing comprehensive healthcare for persons with HIV becomes increasingly complex, including management of multiple comorbidities and the associated challenges of polypharmacy, while not neglecting HIV-related health concerns. Clinicians must address issues specific to persons of childbearing potential, including care during preconception and pregnancy, and to children, adolescents, and transgender and gender-diverse individuals. This guidance from an expert panel of the HIV Medicine Association of the Infectious Diseases Society of America updates previous 2013 primary care guidelines.

Diabetes mellitus in chronic kidney disease: Biomarkers beyond HbA1c to estimate glycemic control and diabetes-dependent morbidity and mortality

Diabetes mellitus (DM) is the leading cause of chronic kidney disease (CKD). Optimal glycemic control contributes to improved outcomes in patients with DM, particularly for microvascular damage, but blood glucose levels are too variable to provide an accurate assessment and instead markers averaging long-term glycemic load are used. The most established glycemic biomarker of long-term glycemic control is HbA1c. Nevertheless, HbA1c has pitfalls that limit its accuracy to estimate glycemic control, including the presence of altered red blood cell survival, hemoglobin glycation and suboptimal performance of HbA1c assays. Alternative methods to evaluate glycemic control in patients with DM include glycated albumin, fructosamine, 1-5 anhydroglucitol, continuous glucose measurement, self-monitoring of blood glucose and random blood glucose concentration measurements. Accordingly, our aim was to review the advantages and pitfalls of these methods in the context of CKD.

The Oral Glucose Tolerance Test: 100 Years Later

For over 100 years, the oral glucose tolerance test (OGTT) has been the cornerstone for detecting prediabetes and type 2 diabetes (T2DM). In recent decades, controversies have arisen identifying internationally acceptable cut points using fasting plasma glucose (FPG), 2-h post-load glucose (2-h PG), and/or HbA1c for defining intermediate hyperglycemia (prediabetes). Despite this, there has been a steadfast global consensus of the 2-h PG for defining dysglycemic states during the OGTT. This article reviews the history of the OGTT and recent advances in its application, including the glucose challenge test and mathematical modeling for determining the shape of the glucose curve. Pitfalls of the FPG, 2-h PG during the OGTT, and HbA1c are considered as well. Finally, the associations between the 30-minute and 1-hour plasma glucose (1-h PG) levels derived from the OGTT and incidence of diabetes and its complications will be reviewed. The considerable evidence base supports modifying current screening and diagnostic recommendations with the use of the 1-h PG. Measurement of the 1-h PG level could increase the likelihood of identifying high-risk individuals when the pancreatic ß-cell function is substantially more intact with the added practical advantage of potentially replacing the conventional 2-h OGTT making it more acceptable in the clinical setting.

High concordance between chart review adjudication and electronic medical record data to identify prevalent and incident diabetes mellitus among persons with and without HIV

BACKGROUND

Electronic medical records (EMR) represent a rich source of data, but the value of EMR for health research relies on accurate ascertainment of clinical diagnoses. Identifying diabetes in EMR is complicated by the variety of accepted diagnostic criteria, some of which can be confounded by conditions such as HIV infection. We compared EMR-based criteria for estimating diabetes prevalence and incidence in the Veterans Health Administration (VHA), overall and by HIV status, against physician chart review and adjudication.

RESEARCH DESIGN AND METHODS

We used laboratory values (serum glucose and hemoglobin A1c% [HbA1c]), ICD-9 codes, and medication records from the United States Veterans Aging Cohort Study Biomarker Cohort to identify veterans with any indication of diabetes in the EMR for subsequent physician adjudication. Sensitivity, specificity, PPV, NPV, and kappa statistics were used to evaluate agreement of EMR-based diabetes diagnoses with chart review adjudicated diagnoses.

RESULTS

EMR entries were reviewed for 1546 persons with HIV (PWH) and 843 HIV-negative participants through 2015. Agreement was at least moderate overall (kappa ≥ 0.42) for all pre-specified measures and among PWH vs HIV-negative, and African-American vs white sub-groups. Having at least one HbA1c ≥6.5% provided substantial agreement with chart adjudication for prevalent and incident diabetes (kappa = 0.89 and 0.73).

CONCLUSIONS

Identification of those with diabetes nationally within the VHA can be used in future studies to evaluate treatments, health outcomes, and adjust for diabetes in epidemiologic studies. Our methodology may provide insights for other organizations seeking to use EMR data for accurate determination of diabetes.

Glycated haemoglobin threshold for dysglycaemia screening, and application to metabolic syndrome diagnosis in HIV-infected Africans

BACKGROUND

Glycated haemoglobin (HbA1c) test has been increasingly promoted as an alternative to fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT) to diagnose dysglycaemia but its performance in HIV-infected Africans has yet to be established. This study aimed to assess the diagnostic accuracy of HbA1c for dysglycaemia including FPG-defined and OGTT-defined dysglycaemia, and OGTT-defined diabetes in HIV-infected Africans, and the effect of HbA1c-predicted dysglycaemia on Joint Interim Statement (JIS)-based prevalent metabolic syndrome (MS).

METHODS

A cross-sectional study included HIV-positive patients recruited across public healthcare facilities in the Western Cape. The recommended HbA1c cut-points were tested alongside the optimal cut-points obtained from receiver operating characteristic curve analyses, while the agreement between the MS criteria were assessed using kappa statistic.

RESULTS

748 participants (157 men), median age 38 years, 93% on anti-retroviral drugs were included. The optimal HbA1c cut-points of 5.75% (39.3 mmol/mol) showed 54% sensitivity, 84% specificity for FPG-defined dysglycaemia, and 52% sensitivity, 85% specificity for OGTT-defined dysglycaemia. The HbA1c value of 5.85% (40.4 mmol/mol) (63% sensitivity, 99% specificity) was optimal for diabetes. The internationally advocated cut-point of 6.5% (48 mmol/mol) had 37% sensitivity and 99% specificity for diabetes, while HbA1c ≥5.7% (≥39 mmol/mol) yielded similar performance with the study-specific cut-point for any dysglycaemia. MS prevalence by the JIS criteria (28.2%) increased to 29.7% when using HbA1c ≥5.75% (≥39.3 mmol/mol) and to 32.9% with HbA1c ≥5.7% (≥39 mmol/mol); agreement between the original and modified criteria was generally good.

CONCLUSIONS

This study agrees with the internationally recommended HbA1c cut-point for detecting dysglycaemia, but not for diabetes in HIV-infected Africans. In line with previous studies in general African populations, our findings suggest that similar factors interfere with HbA1c values regardless of HIV infection status. Replacing FPG-based with HbA1c-predicted dysglycaemia in the JIS criteria to diagnose MS is feasible in HIV-infected Africans.

HbA1c: a review of non-glycaemic variables

Identification of the correlation between HbA1c and diabetic complications has yielded one of the most clinically useful biomarkers. HbA1c has revolutionised the diagnosis and monitoring of diabetes mellitus. However, with widespread adoption of HbA1c has come increasing recognition that non-glycaemic variables can also affect HbA1c, with varying clinical significance. Furthermore, the identification of a discrepancy between predicted and measured HbA1c in some individuals, the so-called 'glycation gap', may be clinically significant. We aimed to review the current body of evidence relating to non-glycaemic variables to quantify any significance and provide subsequent suggestions. A PubMed-based literature search was performed, using a variety of search terms, to retrieve articles detailing the non-glycaemic variables suggested to affect HbA1c. Articles were reviewed to assess the relevance of any findings in clinical practice and where possible guidance is given. A range of non-glycaemic variables have statistically significant effects on HbA1c. While the clinical implications are generally irrelevant, a small number of non-glycaemic variables do have clinically significant effects and alternative biomarkers should be considered instead of, or in addition to, HbA1c. There are a small number of non-glycaemic variables which have a clinically significant effect on HbA1c, However, the vast majority of non-glycaemic variables have no clinical relevance. While clinicians should have an awareness of those non-glycaemic variables with clinical significance, in the vast majority of clinical scenarios HbA1c should continue to be used with confidence.

Endocrinological aspects of HIV infection

PURPOSE

Patients with human immunodeficiency virus (HIV) are living longer with effective antiretroviral therapies and are enjoying near normal life span. Therefore, they are encountering endocrine issues faced by the general population along with those specific to HIV infection. The purpose of this article is to review the common endocrine aspects of HIV infection, and the early detection and management strategies for these complications.

METHODS

Recent literature on HIV and endocrine disease was reviewed.

RESULTS

HIV can influence endocrine glands at several levels. Endocrine glandular function may be altered by the direct effect of HIV viral proteins, through generation of systemic and local cytokines and the inflammatory response and via glandular involvement with opportunistic infections and HIV-related malignancies. Endocrine disorders seen in people with HIV include metabolic issues related to obesity such as diabetes, hyperlipidemia, lipohypertrophy, lipoatrophy and lipodystrophy and contribute significantly to quality of life, morbidity and mortality. In addition, hypogonadism, osteopenia and osteoporosis are also more prevalent in the patients with HIV. Although disorders of hypothalamic-pituitary-adrenal axis resulting in adrenal insufficiency can be life threatening, these along with thyroid dysfunction are being seen less commonly in the antiretroviral therapy (ART) era. ARTs have greatly improved life expectancy in people living with HIV but can also have adverse endocrine effects.

CONCLUSIONS

Clinicians need to have a high index of suspicion for endocrine abnormalities in people with HIV as they can be potentially life threatening if untreated. Endocrine evaluation should be pursued as in the general population, with focus on prevention, early detection and treatment to improve quality of life and longevity.

Diabetes mellitus in HIV-infected patients: fasting glucose, A1c, or oral glucose tolerance test - which method to choose for the diagnosis?

BACKGROUND

Antiretroviral therapy dramatically reduced HIV-related morbidity and mortality, prolonging the lifespan of HIV-infected patients. Greater duration of infection and exposure to antiretroviral therapy makes these patients susceptible to traditional cardio-metabolic risk factors and pathologies. The optimal diagnostic protocol for Diabetes Mellitus in these patients is still controversial. Haemoglobin A1c (HbA1c) has been shown to underestimate glycaemia levels and the oral glucose tolerance test (OGTT) has been shown to reveal cases of glucose metabolism disturbances in patients with normal fasting glucose. Thus, this study aimed to determine the prevalence of prediabetes and diabetes in a population of HIV-infected patients undergoing combined antiretroviral therapy, using three different diagnostic methods (fasting glucose, OGTT and HbA1c), to determine the agreement between the different methods and the characteristics associated with each one.

METHODS

This study analyzed 220 HIV-infected patients on antiretroviral therapy. Patient characteristics were collected using a standardized protocol. Disturbances of glucose homeostasis were defined by the ADA 2017 criteria. Patients were characterized according to the presence or absence of clinical lipodystrophy, and distributed into four different categories, according to the presence, or absence of either clinical lipoatrophy, or abdominal prominence. Insulin resistance was assessed by HOMA-IR and QUICKI indexes. Agreement between the diagnostic methods was assessed by Cohen's kappa coefficient.

RESULTS

There were no patients diagnosed with diabetes with HbA1c. 5.9% prevalence was obtained when OGTT was used, and 3.2% prevalence when fasting glucose was used. Prediabetes had a prevalence of 14.1% when using HbA1c, 24.1% when using OGTT, and 20% when using fasting glucose. In all three methods, glucose homeostasis disturbances were associated with older age and higher resistance to insulin. Regarding other characteristics, associations varied between the three methods. The agreement between them was fair, or slight.

CONCLUSIONS

We observed that HbA1c was the method that diagnosed the least amount of cases and that OGTT was the one that diagnosed the most cases. Accordingly, our results indicate that HbA1c underestimated glycaemia levels in this population and that the use of OGTT might allow an earlier diagnosis of glucose homeostasis disturbances, potentially making it possible to avoid severe complications of DM.

Noncommunicable diseases among HIV-infected persons in low-income and middle-income countries: a systematic review and meta-analysis

OBJECTIVE

To appropriately identify and treat noncommunicable diseases (NCDs) among persons living with HIV (PLHIV) in low-and-middle-income countries (LMICs), it is imperative to understand the burden of NCDs among PLHIV in LMICs and the current management of the diseases.

DESIGN

Systematic review and meta-analysis.

METHODS

We examined peer-reviewed literature published between 1 January 2010 and 31 December 2016 to assess currently available evidence regarding HIV and four selected NCDs (cardiovascular disease, cervical cancer, depression, and diabetes) in LMICs with a focus on sub-Saharan Africa. The databases, PubMed/MEDLINE, Cochrane Review, and Scopus, were searched to identify relevant literature. For conditions with adequate data available, pooled estimates for prevalence were generated using random fixed effects models.

RESULTS

Six thousand one hundred and forty-three abstracts were reviewed, 377 had potentially relevant prevalence data and 141 were included in the summary; 57 were selected for quantitative analysis. Pooled estimates for NCD prevalence were hypertension 21.2% (95% CI 16.3-27.1), hypercholesterolemia 22.2% (95% CI 14.7-32.1), elevated low-density lipoprotein 23.2% (95% CI 15.2-33.6), hypertriglyceridemia 27.2% (95% CI 20.7-34.8), low high-density lipoprotein 52.3% (95% CI 35.6-62.8), obesity 7.8% (95% CI 4.3-13.9), and depression 24.4% (95% CI 12.5-42.1). Invasive cervical cancer and diabetes prevalence were 1.3-1.7 and 1.3-18%, respectively. Few NCD-HIV integrated programs with screening and management approaches that are contextually appropriate for resource-limited settings exist.

CONCLUSION

Improved data collection and surveillance of NCDs among PLHIV in LMICs are necessary to inform integrated HIV/NCD care models. Although efforts to integrate care exist, further research is needed to optimize the efficacy of these programs.

The effect of HIV infection on glycaemia and renal function in type 2 diabetic patients

BACKGROUND

Infection with, and treatment of HIV is associated with effects on glycaemia and renal function. The purpose of this study was therefore to compare glycaemic control and albuminuria in HIV-positive and HIV-negative type 2 diabetic patients.

MATERIALS AND METHODS

Diabetic patients with and without HIV infection were recruited from a diabetic clinic at Chris Hani Baragwanath Hospital in Soweto, South Africa. Data was collected on weight, height, HbA1c, fasting glucose, urine albumin:creatinine ratio, HIV status, CD4 counts, viral load and concomitant therapies. Multivariable regression analysis was used to isolate the determinants of fasting glucose and HbA1c levels and risk factors for albuminuria.

RESULTS

Data were collected from 106 HIV-positive and 214 HIV-negative diabetics. All HIV infected subjects were receiving anti-retroviral therapy. The determinants of fasting glucose levels (log) were HIV infection (β = 0.04, p = 0.01) and use of anti-hypertensive agents (β = 0.07, p = 0.0006), whilst for HbA1c levels (log) they were HIV infection (β = -0.03, p = 0.03), BMI (β = 0.004, p = 0.0005), statin use (β = 0.04, p = 0.002) and glucose levels (β = 0.01, p<0.0005). In HIV-positive subjects, CD4 counts were negatively associated with glucose levels (β = -0.0002, p = 0.03). The risk factors for albuminuria were (odds ratio [95% CIs]) dyslipidaemia (1.94 [1.09, 3.44], p = 0.02) and HbA1c levels (1.24 [1.12, 1.38], p<0.0001).

DISCUSSION

These data suggest that glycaemic control is worse in type 2 diabetic subjects with HIV infection and that HbA1c underestimates glycaemia in these patients. Albuminuria was not associated with HIV-positivity. The negative relationship of CD4 counts with glucose levels may reflect viral removal and easing of the associated inflammatory response. It is possible that the association of statin and anti-hypertensive therapies with high HbA1c and glucose levels, respectively, is due to such therapies being given largely to subjects with poor glycaemic control.

Management of drug-resistant tuberculosis in special sub-populations including those with HIV co-infection, pregnancy, diabetes, organ-specific dysfunction, and in the critically ill

Tuberculosis remains a major problem globally, and is the leading cause of death from an infectious agent. Drug-resistant tuberculosis threatens to marginalise the substantial gains that have recently been made in the fight against tuberculosis. Drug-resistant TB has significant associated morbidity and a high mortality, with only half of all multidrug-resistant TB patients achieving a successful treatment outcome. Patients with drug-resistant TB in resource-poor settings are now gaining access to newer and repurposed anti-tuberculosis drugs such as bedaquiline, delamanid and linezolid. However, with ever increasing rates of co-morbidity, there is little guidance on how to manage complex patients with drug-resistant TB. We address that knowledge gap, and outline principles underpinning the management of drug-resistant TB in special situations including HIV co-infection, pregnancy, renal disease, liver disease, diabetes, and in the critically ill.

Non-Communicable Disease Preventive Screening by HIV Care Model

Importance

The Human Immunodeficiency Virus (HIV) epidemic has evolved, with an increasing non-communicable disease (NCD) burden emerging and need for long-term management, yet there are limited data to help delineate the optimal care model to screen for NCDs for this patient population.

Objective

The primary aim was to compare rates of NCD preventive screening in persons living with HIV/AIDS (PLWHA) by type of HIV care model, focusing on metabolic/cardiovascular disease (CVD) and cancer screening. We hypothesized that primary care models that included generalists would have higher preventive screening rates.

Design

Prospective observational cohort study.

Setting

Partners HealthCare System (PHS) encompassing Brigham & Women’s Hospital, Massachusetts General Hospital, and affiliated community health centers.

Participants

PLWHA age >18 engaged in active primary care at PHS.

Exposure

HIV care model categorized as infectious disease (ID) providers only, generalist providers only, or ID plus generalist providers.

Main Outcome(s) and Measures(s)

Odds of screening for metabolic/CVD outcomes including hypertension (HTN), obesity, hyperlipidemia (HL), and diabetes (DM) and cancer including colorectal cancer (CRC), cervical cancer, and breast cancer.

Results

In a cohort of 1565 PLWHA, distribution by HIV care model was 875 ID (56%), 90 generalists (6%), and 600 ID plus generalists (38%). Patients in the generalist group had lower odds of viral suppression but similar CD4 counts and ART exposure as compared with ID and ID plus generalist groups. In analyses adjusting for sociodemographic and clinical covariates and clustering within provider, there were no significant differences in metabolic/CVD or cancer screening rates among the three HIV care models.

Conclusions

There were no notable differences in metabolic/CVD or cancer screening rates by HIV care model after adjusting for sociodemographic and clinical factors. These findings suggest that HIV patients receive similar preventive health care for NCDs independent of HIV care model.

Oral Glucose Tolerance Testing identifies HIV+ infected women with Diabetes Mellitus (DM) not captured by standard DM definition

OBJECTIVE

HIV-infected (HIV+) individuals may have differential risk of diabetes mellitus (DM) compared to the general population, and the optimal diagnostic algorithm for DM in HIV+ persons remains unclear. We aimed to assess the utility of oral glucose tolerance testing (OGTT) for DM diagnosis in a cohort of women with or at risk for HIV infection.

METHODS

Using American Diabetic Association DM definitions, DM prevalence and incidence were assessed among women enrolled in the Women's Interagency HIV Study. DM was defined by 2-hour OGTT ≥ 200 mg/dL (DM_OGTT) or a clinical definition (DM_C) that included any of the following: (i) anti-diabetic medication use or self-reported DM confirmed by either fasting glucose (FG) ≥126 mg/dL or HbA1c ≥ 6.5%, (ii) FG ≥ 126 mg/dL confirmed by a second FG ≥ 126 mg/dL or HbA1c 6.5%, or (iii) HbA1c 6.5% confirmed by FG ≥ 126 mg/dL cohort.

RESULTS

Overall, 390 women (285 HIV+, median age 43 years; 105 HIV-, median age 37 years) were enrolled between 2003-2006. Over half of all women were African American. Using DM_C, DM prevalence rates were 5.6% and 2.8% among HIV+ and HIV- women, respectively. Among HIV+ women, adding DM_OGTT to DM_C increased DM prevalence from 5.6% to 7.4%, a 31% increase in the number of diabetes cases diagnosed (p=0.02). In HIV- women, no additional cases were diagnosed by DM-OGTT.

CONCLUSION

In HIV+ women, OGTT identified DM cases that were not identified by a standardized clinical definition. Further investigation is needed to determine whether OGTT should be considered as an adjunctive tool for DM diagnosis in the setting of HIV infection.

Fructosamine and Hemoglobin A1c Correlations in HIV-Infected Adults in Routine Clinical Care: Impact of Anemia and Albumin Levels

Fructosamine is an alternative method to hemoglobin A1c (HbA1c) for determining average glycemia. However, its use has not been extensively evaluated in persons living with HIV (PLWH). We examined the relationship between HbA1c and fructosamine values, specifically focusing on anemia (which can affect HbA1c) and albumin as a marker of liver disease. We included 345 PLWH from two sites. We examined Spearman rank correlations between fructosamine and HbA1c and performed linear test for trends to compare fructosamine and HbA1c correlations by hemoglobin and albumin quartiles. We examined discrepant individuals with values elevated only on one test. We found a correlation of 0.70 between fructosamine and HbA1c levels. Trend tests for correlations between fructosamine and HbA1c were significant for both albumin (p = 0.05) and hemoglobin (p = 0.01) with the lowest correlations in the lowest hemoglobin quartile. We identified participants with unremarkable HbA1c values but elevated fructosamine values. These discrepant individuals had lower mean hemoglobin levels than those elevated by both tests. We demonstrated a large correlation between HbA1c and fructosamine across a range of hemoglobin and albumin levels. There were discrepant cases particularly among those with lower hemoglobin levels. Future studies are needed to clarify the use of fructosamine for diabetes management in PWLH.

Monitoring HIV-infected Patients with Diabetes: Hemoglobin A1c, Fructosamine, or Glucose?

BACKGROUND

Published studies report inappropriately low hemoglobin A1C (HbA1c) values that underestimate glycemia in HIV patients.

METHODS

We reviewed the charts of all HIV patients with diabetes mellitus (DM) at our clinic. Fifty-nine patients had HbA1c data, of whom 26 patients also had fructosamine data. We compared the most recent HbA1c to finger-stick (FS) glucose averaged over three months, and fructosamine to FS averaged over six weeks. Predicted average glucose (pAG) was calculated as reported by Nathan et al: pAG (mg/dL) = 28.7 × A1C% − 46.7. Data were analyzed using the Statistical Analysis System (SAS) and Kruskal–Wallis test.

RESULTS

HbA1c values underestimated (UE) actual average glucose (aAG) in 19% of these patients and overestimated (OE) aAG in 27%. HbA1c estimated aAG within the established range in only 54% of the patients. There were no statistical differences in the types of HIV medication used in patients with UE, OE, or accurately estimated (AE) glycemia. A Spearman correlation coefficient between HbA1c and aAG was r = 0.53 (P < 0.0001). Correlation between fructosamine and aAG was r = 0.47 (P = 0.016).

CONCLUSIONS

The correlations between HbA1c and aAG and between fructosamine and aAG were weaker than expected, and fructosamine was not more accurate than HbA1c.

Diagnosing and managing diabetes in HIV-infected patients: current concepts

Diabetes mellitus (DM) is a common condition with significant associated morbidity and mortality. DM diagnosis and management among human immunodeficiency virus (HIV)-infected patients is a particularly relevant topic as the HIV-infected population ages and more HIV-infected individuals live with chronic medical comorbidities. Although there is mixed evidence regarding HIV as an independent risk factor for DM, multiple factors related to HIV and its treatment are associated with DM. This review covers the epidemiology of DM in HIV-infected patients, and diagnosis, management, and treatment goals for DM in HIV-infected patients. We highlight the most recent DM treatment guidelines from the American Diabetes Association and the European Association for the Study of Diabetes, emphasizing individualization of DM medication therapy and treatment goals. Finally, we review a comprehensive approach to cardiovascular disease risk reduction in HIV-infected patients with DM and measures to prevent other complications of DM.

Inaccuracy of haemoglobin A1c among HIV-infected men: effects of CD4 cell count, antiretroviral therapies and haematological parameters

BACKGROUND

There is limited evidence that among HIV-infected patients haemoglobin A1c (HbA1c) values may not accurately reflect glycaemia. We assessed HbA1c discordance (observed HbA1c - expected HbA1c) and associated factors among HIV-infected participants in the Multicenter AIDS Cohort Study (MACS).

METHODS

Fasting glucose (FG) and HbA1c were measured at each semi-annual MACS visit since 1999. All HIV-infected and HIV-uninfected men for whom at least one FG and HbA1c pair measurement was available were evaluated. Univariate median regression determined the association between HbA1c and FG by HIV serostatus. The relationship between HbA1c and FG in HIV-uninfected men was used to determine the expected HbA1c. Generalized estimating equations determined factors associated with the Hb1Ac discordance among HIV-infected men. Clinically significant discordance was defined as observed HbA1c - expected HbA1c ≤-0.5%.

RESULTS

Over 13 years, 1500 HIV-uninfected and 1357 HIV-infected men were included, with a median of 11 visits for each participant. At an FG of 125 mg/dL, the median HbA1c among HIV-infected men was 0.21% lower than among HIV-uninfected men and the magnitude of this effect increased with FG >126 mg/dL. Sixty-three percent of HIV-infected men had at least one visit with clinically significant HbA1c discordance, which was independently associated with: low CD4 cell count (<500 cells/mm(3)); a regimen containing a protease inhibitor, a non-nucleoside reverse transcriptase inhibitor or zidovudine; high mean corpuscular volume; and abnormal corpuscular haemoglobin.

CONCLUSION

HbA1c underestimates glycaemia in HIV-infected patients and its use in patients with risk factors for HbA1c discordance may lead to under-diagnosis and to under-treatment of established diabetes mellitus.

The metabolic deterioration that antedates diabetes: personal trajectories of HbA(1c) and fasting glucose as early indicators and possible triggers for intervention

HbA(1c) testing has become an accepted means of diagnosing diabetes as an alternative to blood glucose levels. However, population-based norms of glucose and of HbA(1c) levels do not enable the detection of diabetes at an early enough stage to thwart complications. Personal trajectories of glucose levels show steep increases a number of years prior to diabetes diagnosis. Here, we hypothesize that a comparable time-dependent deviation in an individual's HbA(1c) level may be an early manifestation of disease that should prompt lifestyle modifications. We predict that analysis of personal trajectories of glucose and of HbA(1c) will promote earlier intervention and a greater reduction in disease complications than current standards, which are based on population-based norms.

Association of HIV infection with incident diabetes mellitus: impact of using hemoglobin A1C as a criterion for diabetes

BACKGROUND

Data regarding the association between HIV and diabetes mellitus (DM) are conflicting, with little known regarding the impact of including hemoglobin A1C (A1C) as a criterion for DM.

METHODS

Pooled logistic regression was used to quantify the association between HIV and DM in 1501 HIV-infected and 550 HIV-uninfected participants from the Women's Interagency HIV Study. Incident DM was defined using the following 3 criteria, definition I: fasting glucose (FG) ≥126 mg/dL, anti-DM medication or reporting DM diagnosis (with confirmation by FG ≥126 mg/dL or anti-DM medication); definition II: confirmation with a second FG ≥126 mg/dL, and definition III: addition of A1C ≥6.5% confirmed by FG ≥126 mg/dL or anti-DM medication.

RESULTS

DM incidence per 100 person-years was 2.44, 1.55, and 1.70 for HIV-infected women; 1.89, 0.85, and 1.13 for HIV-uninfected women, using definition I, II, and III, respectively. After adjustment for traditional DM risk factors, HIV infection was associated with 1.23-, 1.90-, and 1.38-fold higher risk of incident DM, respectively; the association reached statistical significance only when confirmation with a second FG ≥126 mg/dL was required. Older age, obesity, and a family history of DM were each consistently and strongly associated with increased DM risk.

CONCLUSIONS

HIV infection is consistently associated with greater risk of DM. Inclusion of an elevated A1C to define DM increases the accuracy of the diagnosis and only slightly attenuates the magnitude of the association otherwise observed between HIV and DM. By contrast, a DM diagnosis made without any confirmatory criteria for FG ≥126 mg/dL overestimates the incidence, while also underestimating the effects of HIV on DM risk, and should be avoided.

HIV infection and glycemic response to newly initiated diabetic medical therapy

OBJECTIVES

Type 2 diabetes (DM2) is increasingly common in HIV-infected individuals. Antiretroviral agents and chronic inflammation may adversely affect glycemic control. However, little is known about the effectiveness of diabetic medical therapy in HIV-infected patients. The objective of this study was to compare the effectiveness of initial diabetic medical therapy in patients with and without HIV infection.

DESIGN

A retrospective cohort study was conducted among adults with DM2 initiating diabetic medications within the Centers for AIDS Research Network of Integrated Clinical Systems cohort.

METHODS

Generalized estimating equations were used to compare changes in hemoglobin A1c (HbA1c) through the year after initiation of therapy, controlling for baseline HbA1c and demographic and clinical covariates.

RESULTS

Two hundred and eighty-six HIV-infected patients and 858 age and sex-matched HIV-uninfected patients initiated diabetic medications during the study period. Overall, patients had an adjusted absolute mean reduction in HbA1c of 1.04% [95% confidence interval (CI) -0.87 to -1.22] during the first year of therapy. HIV-infected patients achieved significantly smaller reductions in HbA1c, with an absolute mean difference of -0.17% (95% CI -0.28 to -0.06; P = 0.003). On subanalyses, HIV-infected patients on a protease inhibitor-based regimen had significantly smaller reductions in HbA1c compared to HIV-uninfected patients (adjusted absolute difference -0.21%, 95% CI -0.35 to -0.08; P = 0.002).

CONCLUSION

Patients with HIV infection who initiate diabetic medical therapy achieve smaller reductions in HbA1c than patients without HIV infection in the course of routine clinical care. This less robust response may in part be related to use of antiretrovirals that exacerbate insulin resistance, specifically protease inhibitors.

Hyperparathyroidism and complications associated with vitamin D deficiency in HIV-infected adults in New York City, New York

Although recent studies report a high prevalence of vitamin D deficiency in HIV-infected adults similar to that in the general population, metabolic complications of vitamin D deficiency may be worsened with HIV infection and remain insufficiently characterized. We conducted a retrospective cross-sectional cohort study to determine prevalence and correlates of vitamin D deficiency and hyperparathyroidism among HIV-infected patients attending an urban clinic. Vitamin D deficiency was defined as 25(OH)-vitamin D <20 ng/ml and insufficiency as 20 to <30 ng/ml, and hyperparathyroidism as parathyroid-hormone >65 pg/ml. We used the X(2) test to compare proportions and logistic regression to assess for associations. Among 463 HIV-infected patients, the prevalence of vitamin D deficiency was 59%. The prevalence of hyperparathyroidism was 30% among patients with vitamin D deficiency, 23% among those with insufficiency, and 12% among those with sufficient vitamin D levels. Vitamin D deficiency was associated with increased odds of hyperparathyroidism. Severe vitamin D deficiency was associated with elevated alkaline phosphatase, a marker for increased bone turnover. Although efavirenz use was associated with vitamin D deficiency, and protease inhibitor use with decreased odds of vitamin D deficiency, there was no statistical difference in rates of hyperparathyroidism stratified by combination antiretroviral therapy (cART) use. Given the increased risk of osteopenia with HIV infection and cART use, vitamin D supplementation for all HIV-infected patients on cART should be prescribed in accordance with the 2011 Endocrine Society guidelines. In HIV-infected patients with severe vitamin D deficiency or hyperparathyroidism, screening for osteomalacia and osteopenia may be warranted.

Drugs affecting HbA1c levels

Glycated hemoglobin (HbA1c) is an important indicator of glycemic control in diabetes mellitus, based on which important diagnostic and therapeutic decisions are routinely made. However, there are several situations in which the level of HbA1c may not faithfully reflect the glycemic control in a given patient. Important among these is the use of certain non-diabetic medications, which can affect the HbA1c levels in different ways. This review focuses on the non-diabetic medications which can inappropriately raise or lower the HbA1c levels, and the postulated mechanisms for the same.

Glycated Hemoglobin A(1c) as screening for diabetes mellitus in HIV-infected individuals

The American Diabetes Association now recommends hemoglobin A(1c) (HbA(1c)) screening for the diagnosis of diabetes. It has been reported that HbA(1c) levels underestimate glycemic levels in HIV-infected persons. We examined the performance of HbA(1c) as a screening test for diabetes in a group of HIV-infected people without diabetes. We conducted a retrospective cross-sectional cohort study among HIV-infected patients determining the sensitivity and specificity of HbA(1c) as a screening test compared to fasting blood glucose (FBG). The effect of treatment regimen on the relationship between HbA(1c) and FBG was assessed by multiple linear regressions. Twenty-two of the 395 patients included in the study were newly diagnosed with diabetes based on FBG≥126 mg/dL. Using a cutoff of HbA(1c)≥6.5%, HbA(1c) had a sensitivity of 40.9% and specificity of 97.5% for identification of incident diabetes. At an HbA(1c) level of 5.8% the product of sensitivity and specificity was maximized, with values of 88.8% and 77.5% respectively. Higher mean cell volume (MCV) values (p=0.02) and current use of a non-nucleoside reverse transcriptase inhibitors (NNRTIs; p=0.02) significantly increased the slope, while PI use significantly decreased the slope (p<0.001), of the linear regression of HbA(1c) compared to FBG. Tenofovir use did not significantly alter the slope or y-intercept of the line. Among HIV-infected nondiabetic patients, HbA(1c) is insensitive, although highly specific for diagnosing diabetes. Current antiretroviral (ART) use has significant and variable influence on the relationship between HbA(1c) and FBG. The use of HbA(1c) in conjunction with FBG may be the best modality to screen for diabetes.

Current controversies in the use of haemoglobin A1c

Haemoglobin A(1c) (HbA(1c)) has recently been adopted by the World Health Organization into its recommended criteria for diabetes diagnosis. Much debate continues regarding the relative benefits and potential disadvantages surrounding the use of HbA(1c) for this purpose. There is a lack of consensus as to whether this alteration to the definition of diabetes is a step forward or whether it could add further confusion and ambiguity to the debate on the method and criteria for the diagnosis of this globally important disease. This review provides a comprehensive overview of the current issues surrounding how HbA(1c) is measured and reported; and of the evidence for and against its use in diagnosis.

Management of the metabolic effects of HIV and HIV drugs

Morphologic and metabolic abnormalities, including subcutaneous adipose tissue wasting, central adipose tissue accumulation, dyslipidemia and disorders of glucose metabolism are common among HIV-infected patients receiving highly active antiretroviral therapy (HAART) and contribute to the risk of cardiovascular disease in this population. The pathogenesis of these disorders is due to complicated interactions between effects of chronic HIV infection, HAART medications and patient factors, including genetic susceptibility. HAART has transformed HIV into a chronic condition for many patients and as a result the majority of HIV-infected patients in many areas of the developed world will soon be aged ≥50 years. Given that metabolic and cardiovascular diseases increase with aging, knowledge of the optimal management of these conditions is essential for practitioners caring for HIV-infected patients, including endocrine subspecialists. This Review highlights the clinical management of these disorders, focusing on the latest evidence regarding the efficacy of treatment strategies, newly available medications and potential interactions between HAART medications and medications used to treat metabolic disorders.

CrbpI modulates glucose homeostasis and pancreas 9-cis-retinoic acid concentrations

Cellular retinol-binding protein type I (CrbpI), encoded by Rpb1, serves as a chaperone of retinol homeostasis, but its physiological effects remain incompletely understood. We show here that the Rbp1(-/-) mouse has disrupted retinoid homeostasis in multiple tissues, with abnormally high 9-cis-retinoic acid (9cRA), a pancreas autacoid that attenuates glucose-stimulated insulin secretion. The Rbp1(-/-) pancreas has increased retinol and intense ectopic expression of Rpb2 mRNA, which encodes CrbpII: both would contribute to increased β-cell 9cRA biosynthesis. 9cRA in Rbp1(-/-) pancreas resists postprandial and glucose-induced decreases. Rbp1(-/-) mice have defective islet expression of genes involved in glucose sensing and insulin secretion, as well as islet α-cell infiltration, which contribute to reduced glucose-stimulated insulin secretion, high glucagon secretion, an abnormally high rate of gluconeogenesis, and hyperglycemia. A diet rich in vitamin A (as in a standard chow diet) increases pancreas 9cRA and impairs glucose tolerance. Crbp1 attenuates the negative impact of vitamin A (retinol) on glucose tolerance, regardless of the dietary retinol content. Rbp1(-/-) mice have an increased rate of fatty acid oxidation and resist obesity when fed a high-fat diet. Thus, glucose homeostasis and energy metabolism rely on Rbp1 expression and its moderation of pancreas retinol and of the autacoid 9cRA.

Insulin resistance in treated HIV infection

Insulin resistance (IR) was one of the first metabolic complications reported with highly active antiretroviral therapy for HIV infection. It continues to be of concern despite the introduction of newer antiretrovirals with safer metabolic profiles and is associated with inflammation and the development of diabetes mellitus. As the HIV-infected population ages, the prevalence of IR is likely to rise. Specific antiretrovirals can increase insulin resistance through two principal mechanisms, either directly by interfering with insulin signalling at the cellular level or indirectly as a consequence of defects in lipid metabolism (lipotoxocity) arising from antiretroviral toxicities such as the IR observed in those with HIV-associated lipodystrophy. There is considerable overlap between different antiretrovirals in their propensity to cause IR making it more difficult to attribute development of IR to a particular antiretroviral medication. In addition, in the setting of a generalised epidemic of obesity that exists in many populations worldwide, HIV-infected patients may be more prone to the consequences of antiretroviral-induced insulin resistance and diabetes mellitus. Optimal screening and treatment strategies for IR in treated HIV infection have not been established. In this article we review current opinion on insulin resistance in HIV and identify potential areas for future research.

Advanced glycation end products inhibit both infection and transmission in trans of HIV-1 from monocyte-derived dendritic cells to autologous T cells

Highly active antiretroviral therapy is associated with carbohydrate metabolic alterations that may lead to diabetes. One consequence of hyperglycemia is the formation of advanced glycation end products (AGEs) that are involved in diabetes complications. We investigated the impact of AGEs on the infection of monocyte-derived dendritic cells (MDDCs) by HIV-1 and the ability of MDDCs to transmit the virus to T cells. We showed that AGEs could inhibit infection of MDDCs with primary R5-tropic HIV-1(Ba-L) by up to 85 ± 9.2% and with primary X4-tropic HIV-1(VN44) by up to 60 ± 8.5%. This inhibitory effect of AGEs was not prevented by a neutralizing anti-receptor for advanced glycation end products (anti-RAGE) Ab, demonstrating a RAGE-independent mechanism. Moreover, AGEs inhibited by 70-80% the transmission in trans of the virus to CD4 T cells. Despite the inhibitory effect of AGEs on both MDDC infection and virus transmission in trans, no inhibition of virus attachment to cell membrane was observed, confirming that attachment and transmission of the virus involve independent mechanisms. The inhibitory effect of AGEs on infection was associated with a RAGE-independent downregulation of CD4 at the cell membrane and by a RAGE-dependent repression of the CXCR4 and CCR5 HIV-1 receptors. AGEs induce the secretion of proinflammatory cytokines IL-6, TNF-α, and IL-12, but not RANTES or MIP-1α, and did not lead to MDDC maturation as demonstrated by the lack of expression of the CD83 molecule. Taken together, our results suggest that AGEs can play an inhibiting role in HIV-1 infection in patients who accumulate circulating AGEs, including patients treated with protease inhibitors that developed diabetes.

Applicability and precautions of use of liver injury biomarker FibroTest. A reappraisal at 7 years of age

BACKGROUND

FibroTest (FT) is a validated biomarker of fibrosis. To assess the applicability rate and to reduce the risk of false positives/negatives (RFPN), security algorithms were developed. The aims were to estimate the prevalence of RFPN and of proven failures, and to identify factors associated with their occurrences.

METHODS

Four populations were studied: 954 blood donors (P1), 7,494 healthy volunteers (P2), 345,695 consecutive worldwide sera (P3), including 24,872 sera analyzed in a tertiary care centre (GHPS) (P4). Analytical procedures of laboratories with RFPN > 5% and charts of P4 patients in with RFPN were reviewed.

RESULTS

The prevalence of RFPN was 0.52% (5/954; 95%CI 0.17-1.22) in P1, 0.51% (38/7494; 0.36-0.70) in P2, and 0.97% (3349/345695; 0.94-1.00) in P3. Three a priori high-risk populations were confirmed: 1.97% in P4, 1.77% in HIV centre and 2.61% in Sub-Saharan origin subjects. RFPN was mostly associated with low haptoglobin (0.46%), and high apolipoproteinA1 (0.21%). A traceability study of a P3 laboratory with RFPFN > 5% permitted to correct analytical procedures.

CONCLUSION

The mean applicability rate of Fibrotest was 99.03%. Independent factors associated with the high risk of false positives/negatives were HIV center, subSaharan origin, and a tertiary care reference centre, although the applicability rate remained above 97%.

Glycated haemoglobin in diabetic women with and without HIV infection: data from the Women's Interagency HIV Study

BACKGROUND

Limited data suggest that glycated haemoglobin (haemoglobin A1c; A1C) values might not reflect glycaemic control accurately in HIV-infected individuals with diabetes.

METHODS

We evaluated repeated measures of paired fasting glucose and A1C values in 315 HIV-infected and 109 HIV-uninfected diabetic participants in the Women's Interagency HIV Study. Generalized estimating equations used log A1C as the outcome variable, with adjustment for log fasting glucose concentration in all models.

RESULTS

An HIV-infected woman on average had 0.9868 times as much A1C (that is, 1.32% lower; 95% confidence interval 0.9734-0.9904) as an HIV-uninfected woman with the same log fasting glucose concentration. In multivariate analyses, HIV serostatus was not associated, but White, other non-Black race, and higher red blood cell mean corpuscular volume (MCV) were statistically associated with lower A1C values. Use of diabetic medication was associated with higher A1C values. In multivariate analyses restricted to HIV-infected women, White and other race, higher MCV, and HCV viraemia were associated with lower A1C values, whereas older age, use of diabetic medications and higher CD4(+) T-cell count were associated with higher A1C values. Use of combination antiretroviral therapy, protease inhibitors, zidovudine, stavudine or abacavir was not associated with A1C values.

CONCLUSIONS

A1C values were modestly lower in HIV-infected diabetic women relative to HIV-uninfected diabetic women after adjustment for fasting glucose concentration. The difference was abrogated by adjustment for MCV, race and diabetic medication use. Our data suggest that in clinical practice A1C gives a reasonably accurate refection of glycaemic control in HIV-infected diabetic women.

The effects of intermittent, CD4-guided antiretroviral therapy on body composition and metabolic parameters

OBJECTIVE

To assess the effects of decreased antiretroviral therapy exposure on body fat and metabolic parameters.

DESIGN

Substudy of the Strategies for Management of Anti-Retroviral Therapy study, in which participants were randomized to intermittent CD4-guided [Drug Conservation (DC) group] or to continuous [Viral Suppression (VS) group] antiretroviral therapy.

METHODS

Participants at 33 sites were coenrolled in the Strategies for Management of Anti-Retroviral Therapy Body Composition substudy. Regional fat was assessed annually by whole-body dual-energy X-ray absorptiometry and abdominal computed tomography. Fasting metabolic parameters were assessed at months 4, 8, and annually. Treatment groups were compared for changes in fat and metabolic markers using longitudinal mixed models.

RESULTS

Two hundred and seventy-five patients were randomized to the DC (n = 142) or VS (n = 133) group and followed for a median of 2.0 years. By month 12, limb fat (DC-VS difference 9.8%, 95% confidence interval 3.5-16.1; P = 0.003) and subcutaneous abdominal fat (DC-VS difference 14.3 cm, 95% confidence interval -0.1 to 28.7; P = 0.05) increased in the DC group. There was no treatment difference in visceral abdominal fat (DC-VS difference -2.1%, 95% confidence interval -13.5 to 9.4; P = 0.72). Lipids significantly decreased in the DC group by month 4 and treatment differences persisted throughout follow-up (P < or = 0.001). By 12 months, hemoglobin A1C increased in the DC (+0.3%) and remained stable in the VS group (P = 0.003); the treatment difference remained significant throughout follow-up (P = 0.02).

CONCLUSION

After 12 months, intermittent antiretroviral therapy increased subcutaneous fat, had no effect on visceral abdominal fat, decreased plasma lipids, and increased hemoglobin A1C compared with continuous antiretroviral therapy.

A1C underestimates glycemia in HIV infection

OBJECTIVE

The objective of this study was to determine the relationship between A1C and glycemia in HIV infection.

RESEARCH DESIGN AND METHODS

We completed a prospective cross-sectional study of 100 HIV-infected adults with type 2 diabetes (77%) or fasting hyperglycemia (23%) with measured glucose, A1C, mean corpuscular volume (MCV), and fructosamine. A total of 200 HIV-uninfected type 2 diabetic subjects matched for key demographic characteristics served as control subjects.

RESULTS

Relative to the control subjects, A1C underestimated glucose by 29 +/- 4 mg/dl in the HIV-infected subjects. Current nucleoside reverse transcriptase inhibitors (NRTIs), higher MCV and hemoglobin, and lower HIV RNA and haptoglobin were associated with greater A1C-glucose discordance. However, only MCV and current NTRI use, in particular abacavir, remained significant predictors in multivariate analyses. Fructosamine more closely reflected glycemia in the HIV-infected subjects.

CONCLUSIONS

A1C underestimates glycemia in HIV-infected patients and is related to NRTI use. Use of abacavir and increased MCV were key correlates in multivariate analyses. Fructosamine may be more appropriate in this setting.

Review of hemoglobin A(1c) in the management of diabetes

Hemoglobin HbA(1c) (A(1c)) has been used clinically since the 1980s as a test of glycemic control in individuals with diabetes. The Diabetes Control and Complications Trial (DCCT) demonstrated that tight glycemic control, quantified by lower blood glucose and A(1c) levels, reduced the risk of the development of complications from diabetes. Subsequently, standardization of A(1c) measurement was introduced in different countries to ensure accuracy in A(1c) results. Recently, the International Federation of Clinical Chemists (IFCC) introduced a more precise measurement of A(1c) , which has gained international acceptance. However, if the IFCC A(1c) result is expressed as a percentage, it is lower than the current DCCT-aligned A(1c) result, which may lead to confusion and deterioration in diabetic control. Alternative methods of reporting have been proposed, including A(1c) -derived average glucose (ADAG), which derives an average glucose from the A(1c) result. Herein, we review A(1c) , the components involved in A(1c) formation, and the interindividual and assay variations that can lead to differences in A(1c) results, despite comparable glycemic control. We discuss the proposed introduction of ADAG as a surrogate for A(1c) reporting, review imprecisions that may result, and suggest alternative clinical approaches.

Factitious biochemical measurements resulting from hematologic conditions

Factitious laboratory results often lead to unnecessary testing or treatment. This brief review of factitious biochemical results due to preexisting hematologic conditions focuses on the mechanisms underlying the factitious results and suggests ways to prevent them. An observant pathologist identifies these errors, intervenes in a timely fashion, investigates the sources of error diligently, and institutes measures to prevent their recurrence.

Inferiority of IL-2 alone versus IL-2 with HAART in maintaining CD4 T cell counts during HAART interruption: a randomized controlled trial

OBJECTIVE

To evaluate whether interleukin (IL)-2 in patients with chronic HIV infection can maintain CD4 T cell counts during 6 months of HAART interruption.

DESIGN

Prospective, randomized, controlled, open-label phase II noninferiority trial comparing IL-2 with HAART interruption or continuous HAART.

METHODS

Forty-one IL-2-experienced (three or more prior cycles) HIV-1-infected adults with CD4 cell count at least 500 cells/microl were randomized in the ratio 2: 1 to interrupted (I = 27) or continuous (C = 14) HAART for 6 months following an initial IL-2 cycle. Subsequent IL-2 cycles were triggered by CD4 T cell counts less than 90% of baseline. Immune, metabolic, and quality of life indices were compared (Mann-Whitney and Fisher's exact tests), defining noninferiority as a percentage difference (C- I) in treatment success (CD4 T cells > or =90% of baseline at 6 months) with a 95% confidence interval (CI) lower limit greater than -20%.

RESULTS

Demographic and immune parameters were similar between the groups at baseline. Median CD4 T cell count, HIV viral load, and treatment success differed significantly at 6 months (I: 866 cells/microl, 39,389 copies/ml, 48.1%; C: 1246 cells/microl, <50 copies/ml, 92.3%; P < or = 0.001). Group I was inferior to C (% difference = -44.2%; 95% CI: -64.2%, -11.2%; P = 0.013). Minor statistically significant differences in HgbA1c and energy level occurred at 6 months (I > C). Following HAART interruption, single cases of acute retroviral syndrome, secondary syphilis, non-Hodgkin's lymphoma, and Kaposi's sarcoma recurrence were observed.

CONCLUSION

IL-2 alone was inferior to IL-2 with HAART in maintaining baseline CD4 T cell counts. HAART interruption had a small impact on metabolic parameters and quality of life.

[Inappropriate low glycated hemoglobin and hemolysis]

Hemoglobin A1c (HbA1c), measured regularly in the patients with diabetes, is the major form of stable glycated hemoglobin and has to be maintained below 6.5% to prevent or decrease the risk of chronic complications. HbA1c reflects mean blood glucose levels of the previous 3 months. We report the case of a particularly low HbA1c in a diabetic patient despite high plasma glucose levels, that was induced by auto-immune hemolysis related to an Evans syndrome. All hemolytic disorders can be responsible for falsely reassuring HbA1c values. Clinicians must be aware that hematologic status has to be considered for the correct interpretation of HbA1c results.

No relationship between mean plasma glucose and glycated haemoglobin in patients with cystic fibrosis-related diabetes

AIM

Cystic fibrosis-related diabetes (CFRD) prevalence has increased dramatically with the improved life expectancy of patients with cystic fibrosis (CF). Glycated haemoglobin (HbA(1c)) is an important tool for monitoring blood glucose control but, unlike in type 1 and type 2 diabetes, a correlation between HbA(1c), fructosamine and mean plasma glucose has not been clearly established in CF. This study aimed to examine the relationship between mean plasma glucose and HbA(1c) or fructosamine in stable patients with CFRD.

METHODS

Fifteen type 1 diabetes and 13 CFRD patients (HbA(1c)<9.0%; no anaemia), matched for age and body mass index (BMI), provided 72 capillary blood glucose profiles taken 3days/month for three months. At the end of this time, HbA(1c) and fructosamine were measured. Mean plasma glucose was estimated using the Diabetes Control and Complications Trial (DCCT) conversion formula, and linear regressions carried out to establish its relationship with HbA(1c) and fructosamine.

RESULTS

In type 1 diabetes patients, mean plasma glucose correlated significantly with HbA(1c) (r=0.68; P=0.005). In CFRD patients, no correlation was found between mean plasma glucose and HbA(1c) (r=0.24; P=0.460). Also, no association was found between mean plasma glucose, representing the month before blood sampling, and fructosamine in either group.

CONCLUSION

Unlike in type 1 diabetes, HbA(1c) did not correlate with mean plasma glucose in CFRD subjects. Thus, having a normal HbA(1c) may not be sufficient to indicate a low risk of diabetes complications in CFRD. Further studies are required to explain such a discrepancy.

A New Zealand linkage study examining the associations between A1C concentration and mortality

OBJECTIVE

To examine associations between A1C concentration and mortality in a New Zealand population.

RESEARCH DESIGN AND METHODS

During a Hepatitis Foundation screening campaign for hepatitis B (1999-2001), participants were offered A1C testing. The participants were anonymously linked to the national mortality collection to 31 December 2004. Hazard ratios (HRs) and 95% CIs adjusted for age, ethnicity, smoking, and sex were estimated using Cox regression.

RESULTS

There were 47,904 participants (71% Mâori, 12% Pacific, 5% Asian, and 12% other). A1C measurements were categorized as <4.0% (n = 142), 4.0 to <5.0% (reference category; n = 12,867), 5.0 to <6.0% (n = 30,222), 6.0 to <7.0% (n = 2,669), and >or=7.0% (n = 1,596); there were also 408 participants with a previous diabetes diagnosis. During the follow-up period, 815 individuals died. In those without a prior diabetes diagnosis, there were steadily increasing HRs from the A1C reference category to the highest category (>or=7.0%; HR 2.36 [95% CI 1.72-3.25]). As well as all-cause mortality, A1C was associated with mortality from diseases of the circulatory system; endocrine, nutritional, metabolic, and immunity disorders; and other and unknown causes. Mortality was also elevated in those with a prior diabetes diagnosis (5.19 [3.67-7.35]), but this was only partially explained by their elevated A1C levels.

CONCLUSIONS

This is the largest study to date of A1C levels and subsequent mortality risk. It confirms previous findings that A1C levels are strongly associated with subsequent mortality in both men and women without a prior diabetes diagnosis.