Prevalence of dysmenorrhea and associated risk factors among university students in Zimbabwe

BACKGROUND

Dysmenorrhea is an often incapacitating condition that is characterized by painful menstruation and general body malaise. In Zimbabwe, this condition is understudied, and its associated risk factors are poorly understood.

OBJECTIVES

To investigate the prevalence and associated risk factors of dysmenorrhea among female students at Midlands State University in Zimbabwe.

DESIGN

This is a cross-sectional study that employed simple random sampling technique to obtain data from 382 students using pretested and self-administered questionnaires.

METHODS

Data were analyzed using STATA version 16. Associations between dysmenorrhea, menstrual, sociodemographic, and lifestyle characteristics were measured using chi-square test and logistic regression model.

RESULTS

The prevalence of dysmenorrhea was 75.9%, with 28.6% of sufferers describing their pain as severe. Dysmenorrhea significantly affected the school/daily activities of respondents (χ2 = 18.22, p < 0.001). Family history (χ2 = 4.28, p = 0.04), age of menarche (χ2 = 14.8, p < 0.001), regularity of menstrual cycle (χ2 = 18.1, p < 0.001), and parity (χ2 = 8.8, p = 0.03) were associated with the prevalence of dysmenorrhea. The risk of developing dysmenorrhea almost doubled with positive family history (prevalence odds ratio = 1.68 (95% confidence interval: 1.03 to 2.75, p = 0.040)); increased with decrease in age of menarche (prevalence odds ratio = 0.19 (95% confidence interval: 0.10 to 0.45, p < 0.001)) and decreased with increase in parity (prevalence odds ratio = 0.15 (95% confidence interval: 0.03 to 0.82, p = 0.029)). However, the risk was low among those with irregular menstrual cycles (prevalence odds ratio = 0.14 (95% confidence interval: 0.10 to 0.33, p < 0.001)). Physical exercise, smoking, alcohol, and coffee consumption were not associated with the prevalence of dysmenorrhea (p > 0.05).

CONCLUSION

Dysmenorrhea is common among female students at Midlands State University, and it significantly affects their academic activities. Family history, regular menstrual cycle, nulliparity, and lower age of menarche were risk factors. More awareness is recommended including studies on impact and management strategies.

The effect of increased mobility on SARS-CoV-2 transmission: a descriptive study of the trends of COVID-19 in Zimbabwe between December 2020 and January 2021

Introduction

when the first cases of COVID-19 were reported in Zimbabwe in March 2020, the local outbreak was characterised by an insidious increase in national caseload. This first wave was mainly attributable to imported cases, peaking around July 2020. By October 2020, the number of cases reported daily had declined to less than 100 cases per day signalling the end of the first wave. This pattern mirrored the global trends. In December 2020, reports of new COVID-19 variants emerged and coincided with the beginning of the second wave within the ongoing pandemic. This paper reports on the analysis conducted on the new wave of COVID-19 beginning December 2020 to January 2021. The objective of this study was to document the evolving presumptive second wave of the COVID-19 pandemic in Zimbabwe from December 2020 to January 2021.

Methods

this is a retrospective analysis of secondary data extracted from the daily situation reports published by the Ministry of Health and Child Welfare, Zimbabwe and World Health Organization Country Office, Zimbabwe. The period under consideration started from 1^st December 2020 to 31^st January 2021.

Results

there was a 333% increase in the number of confirmed COVID-19 cases starting 1^st December 2020, to 31^st January 2021. These new cases were mainly attributed to community transmission though there were a few imported cases. There was a 439% increase in the absolute number of deaths; however, the case fatality rate remained low at 3.6%, and comparable to that from other countries. Harare, Bulawayo and Manical and provinces accounted for 60% of the case burden, with the other seven provinces only accounting for 40%. By mid-January, the number of incident COVID-19 cases started to decline significantly, to levels similar to the residual levels seen during the first wave.

Conclusion

the second wave, which lasted a period of less than 2 months, had a steep rise and sharp decline in the incident cases and fatalities. The steep rise was attributable to increased mobility, with a consequent increase in the chains of community transmission. The declines, noted from mid-January 2021, may be partly attributable to a strict national lockdown, though more in-depth exploration of the drivers of transmission is needed to tailor effective interventions for future control. Differentiated strategies maybe needed according to the case burdens in the different provinces. In anticipation of further waves, the introduction of safe and effective vaccines might be the game changer if the vaccines are widely availed to the population to levels adequate to achieve herd immunity. Meanwhile, infection prevention and control guidelines must continue to be observed.

A descriptive study of the trends of COVID-19 in Zimbabwe from March-June 2020: policy and strategy implications

INTRODUCTION

the first cases of COVID-19 were reported in China in December 2019. Since then, the disease has evolved to become a global pandemic. Zimbabwe reported its first case on 20th March 2020, and the number has been increasing steadily. However, Zimbabwe has not witnessed the exponential growth witnessed in other countries so far, and the trajectory seems different. We set out to describe the epidemiological trends of COVID-19 in Zimbabwe from when the first case was confirmed to June 2020.

METHODS

data were collected from daily situation reports that were published by the Zimbabwean Ministry of Health and Child Care from 20th March to 27th June 2020. Missing data on the daily situation reports was not imputed.

RESULTS

as of 27th June 2020, Zimbabwe had 567 confirmed COVID-19 cases. Eighty-two percent of these were returning residents and 18% were local transmission. The testing was heavily skewed towards returnees despite a comprehensive testing strategy. Of the confirmed cases, 142 were reported as recovered. However, demographic data for the cases were missing from the reports. It was not possible to estimate the probable period of infection of an active case, and case fatality in Zimbabwe was about 1% for the first 4 months of the pandemic.

CONCLUSION

the epidemiological trends of COVID-19 experienced in Zimbabwe between March and June 2020 are somewhat different from what has been observed elsewhere. Further research to determine the reasons for the differences is warranted, to inform public health practice and tailor make suitable interventions.

A descriptive study of the trends of COVID-19 in Zimbabwe from March - June 2020: policy and strategy implications

Introduction

the first cases of COVID-19 were reported in China in December 2019. Since then, the disease has evolved to become a global pandemic. Zimbabwe reported its first case on 20^th March 2020, and the number has been increasing steadily. However, Zimbabwe has not witnessed the exponential growth witnessed in other countries so far, and the trajectory seems different. We set out to describe the epidemiological trends of COVID-19 in Zimbabwe from when the first case was confirmed to June 2020.

Methods

data were collected from daily situation reports that were published by the Zimbabwean Ministry of Health and Child Care from 20^th March to 27^th June 2020. Missing data on the daily situation reports was not imputed.

Results

as of 27^th June 2020, Zimbabwe had 567 confirmed COVID-19 cases. Eighty-two percent of these were returning residents and 18% were local transmission. The testing was heavily skewed towards returnees despite a comprehensive testing strategy. Of the confirmed cases, 142 were reported as recovered. However, demographic data for the cases were missing from the reports. It was not possible to estimate the probable period of infection of an active case, and case fatality in Zimbabwe was about 1% for the first 4 months of the pandemic.

Conclusion

the epidemiological trends of COVID-19 experienced in Zimbabwe between March and June 2020 are somewhat different from what has been observed elsewhere. Further research to determine the reasons for the differences is warranted, to inform public health practice and tailor make suitable interventions.

Diversity of rotavirus strains circulating in children under five years of age who presented with acute gastroenteritis before and after rotavirus vaccine introduction, University Teaching Hospital, Lusaka, Zambia, 2008-2015

BACKGROUND

Following the introduction of rotavirus vaccine into the routine immunization schedule, the burden of rotavirus disease has significantly reduced in Zambia. Although rotavirus vaccines appear to confer good cross-protection against both vaccine and non-vaccine strains, concerns about strain replacement following vaccine implementation remain. We describe the diversity of the circulating rotavirus strains before and after the Rotarix® vaccine was introduced in Lusaka from January 2012.

METHODS

Under five children were enrolled through active surveillance at University Teaching Hospital using a standardized WHO case investigation form. Stool samples were collected from children who presented with ≥3 loose stool in 24 h and were admitted to the hospital for acute gastroenteritis as a primary illness. Samples were tested for group A rotavirus antigen enzyme-linked immunosorbent assay. Randomly selected rotavirus positive samples were analysed by reverse transcription polymerase chain reaction for G and P genotyping and and Nucleotide sequencing was used to confirm some mixed infections.

RESULTS

A total of 4150 cases were enrolled and stool samples were collected from 4066 (98%) children between 2008 and 2011, before the vaccine was introduced. Rotavirus antigen was detected in 1561/4066 (38%). After vaccine introduction (2012 to 2015), 3168 cases were enrolled, 3092 (98%) samples were collected, and 977/3092 (32%) were positive for rotavirus. The most common G and P genotype combinations before vaccine introduction were G1P[8] (49%) in 2008; G12P[6] (24%) and G9P[8] (22%) in 2009; mixed rotavirus infections (32%) and G9P[8] (20%) in 2010, and G1P[6] (46%), G9P[6] (16%) and mixed infections (20%) in 2011. The predominant strains after vaccine introduction were G1P[8] (25%), G2P[4] (28%) and G2P[6] (23%) in 2012; G2P[4] (36%) and G2P[6] (44%) in 2013; G1P[8] (43%), G2P[4] (9%), and G2P[6] (24%) in 2014, while G2P[4] (54%) and G2P[6] (20%) continued to circulate in 2015.

CONCLUSION

These continual changes in the predominant strains suggest natural secular variation in circulating rotavirus strains post-vaccine introduction. These findings highlight the need for ongoing surveillance to continue monitoring how vaccine use affects strain evolution over a longer period of time and assess any normal seasonal fluctuations of the rotavirus strains.

Implementation research: reactive mass vaccination with single-dose oral cholera vaccine, Zambia

Objective

To describe the implementation and feasibility of an innovative mass vaccination strategy – based on single-dose oral cholera vaccine – to curb a cholera epidemic in a large urban setting.

Method

In April 2016, in the early stages of a cholera outbreak in Lusaka, Zambia, the health ministry collaborated with Médecins Sans Frontières and the World Health Organization in organizing a mass vaccination campaign, based on single-dose oral cholera vaccine. Over a period of 17 days, partners mobilized 1700 health ministry staff and community volunteers for community sensitization, social mobilization and vaccination activities in 10 townships. On each day, doses of vaccine were delivered to vaccination sites and administrative coverage was estimated.

Findings

Overall, vaccination teams administered 424 100 doses of vaccine to an estimated target population of 578 043, resulting in an estimated administrative coverage of 73.4%. After the campaign, few cholera cases were reported and there was no evidence of the disease spreading within the vaccinated areas. The total cost of the campaign – 2.31 United States dollars (US$) per dose – included the relatively low cost of local delivery – US$ 0.41 per dose.

Conclusion

We found that an early and large-scale targeted reactive campaign using a single-dose oral vaccine, organized in response to a cholera epidemic within a large city, to be feasible and appeared effective. While cholera vaccines remain in short supply, the maximization of the number of vaccines in response to a cholera epidemic, by the use of just one dose per member of an at-risk community, should be considered.

Dengue fever outbreaks in Eritrea, 2005-2015: A case for strengthening surveillance, control and reporting

Background

The geographic distribution and burden of dengue is increasing globally. This study aims to evaluate dengue outbreaks and to substantiate the need for strengthened surveillance, reporting and control in Eritrea.

Methods

Data from two cross-sectional dengue epidemic investigations in 2005 and 2010 were analyzed. Samples were tested for dengue virus-specific IgM and IgG antibodies using capture enzyme-linked immunosorbent assays. Dengue vectors’ breeding attributes were characterized and epidemic risk indices determined. National routine surveillance weekly reports from 2005 to the second quarter of 2015 were analyzed for spatiotemporal trends.

Results

Dengue outbreaks increased in Eritrea from 2005 to 2015 with clinical presentation varying markedly among patients. The house and container indices for Aedes aegypti were 40 and 39.6 % respectively, with containers having A. aeqypti varying significantly (P < 0.04). Serum from 33.3 % (n = 15) and 88 % (n = 26) of clinical dengue cases in Aroget sub-Zoba (district) of Gash Barka Zoba (region) contained anti-DENV IgM antibody in 2005 and 2006, respectively. The national surveillance data from 2005 to 2015 indicate an overall spatiotemporal increase of dengue fever.

Conclusions

The increase in dengue outbreaks has been confirmed in Eritrea and necessitates strengthening of surveillance and health worker and laboratory capacity, as well as targeted vector control interventions.

Underestimation of prevalence of raised blood sugar from history compared to biochemical estimation: support for the WHO rule of halves in a population based survey in Eritrea of 2009

To ascertain the prevalence of diabetes mellitus from history and biochemical estimation so as to attest the WHO Rule of halves in a lean population. A population based national survey on diabetes mellitus was carried out in 2009. History and fingerpicks blood analysis were examined according to recommended procedures of the WHO STEPwise approach and the WHO recommended automated machine to compare the two modalities of estimating diabetes prevalence. Over 6000 people with a response rate of 95 % and a prevalence of raised blood glucose of 5.0 %. The prevalence from history of raised blood sugar was 2.2 %. Less than half (47 %) of the persons with high blood glucose were aware of their status with less than half on treatment. Of those on treatment less than half (30 %) were well controlled. Prevalence of raised fasting blood glucose was more than double that estimated from history, with less than half of the people aware of their status and of those on treatment nearly half are under good control. The underestimation of the disease through history supports the WHO rule of halves and calls for the use of biochemical tests when estimating prevalence of diabetes in the general population or at least doubling the rate from history alone.

Comparison of exercise-induced hypertension in low birth weight and normal birth weight young black adults in Zimbabwe

AIM

The objective of the study was to compare blood pressure changes during exercise between low and normal birth weight young Black adults.

METHODS

Eighty medical students in their first and second year who had neonatal clinic cards as proof of birth weight were included in the study. Resting blood pressures and heart rates were recorded. Participants then underwent a multistage 9-minute exercise stress test while blood pressure responses were recorded at 3-minute intervals. The study was conducted in the Department of Physiology, University of Zimbabwe, College of Health Sciences, Harare, Zimbabwe.

RESULTS

Of the 80 subjects recruited, 34 had low birth weight (LBW), 26 of these were female and 8 were male. The proportion of LBW individuals, 62% (n = 21), who developed exercise-induced hypertension (EIH) was significantly higher (p < 0.05) than the proportion of those with normal birth weight (NBW), 32% (n = 11). In addition to LBW being significantly associated with EIH (χ2 test p < 0.05, odds ratio 7.5) compared with NBW, the LBW group had a significantly higher (p < 0.05) and exaggerated systolic and diastolic response in stages I and II of the exercise protocol compared with the NBW group.

CONCLUSION

LBW was associated with EIH in these young Black adults.

Profile of patients with diabetes in Eritrea: results of first phase registry analyses

A cross-sectional descriptive study was done on patients recently entered into the National Diabetes Registry in Eritrea where the prevalence was estimated to be 2.2% based on patient information in 2004. Of the 627 patients with diabetes, two thirds were type 2. Although type 1 had poorer control (42.9%) than type 2 (29.9%), some of the risk factors such as cholesterol (43.4 vs. 28.2%), triglyceride (23.4 vs. 12.8%), hypertension (55.2 vs. 12.7%) as well as BMI and waist/hip ratio were higher in type 2 than type 1. More than one-third (41.2%) of patients with type 2 compared to type 1 (19.5%) had complications, the commonest being retinopathy (33%) followed by foot ulcers (14%) and neuropathy (4%). Many of the diabetic patients demonstrated the presence of the metabolic syndrome components such as hypertension, obesity and dyslipidemia. The authors conclude that diabetes registry is invaluable in providing evidence-based prevention and control of the disease.

Cracking the whip on childhood mortality--role of the specialized neonatal unit in Eritrea

Health care services in developing countries are being challenged by high childhood mortality rates. Although there have been tremendous strides made in reducing infant mortality rates largely due to vaccinations and improved standards of living, a lot remains to be done to reduce neonatal mortality. Achievement of the Millennium Development Goal (MDG) number 4 on childhood mortality will remain unattainable in most developing countries unless purpose based interventions targeted at reducing neonatal mortality are instituted. This viewpoint is based on the experiences gained in Eritrea, a country that gained independence less than twenty years ago following a protracted war that left a trail of destruction of infrastructure in general and health facilities in particular. War that broke out with Ethiopia less than 10 years into its independence and border conflicts followed by a no peace no war stalemate situation aggravated by frequent droughts have continued to throttle economic recovery, reconstruction and rehabilitative efforts. The population is estimated at 3.5 million comprising of nine ethnic groups who speak different languages. The country has a surface area of 124,000 km2 which shares borders with Sudan, Ethiopia, Djibouti and the Red Sea.

CONCLUSION

Attainment of the MDG number 4 on reduction of childhood mortality can be achieved by addressing morbidities of the neonate where the bottle neck currently appears to be sited.

Challenges in training the ideal Doctor for Africa: lessons learned from Zimbabwe

BACKGROUND

Limited competencies among doctors and reduced numbers from medical migration in Africa could be corrected through innovative curricula and retention of trained manpower. The University of Zimbabwe Medical School simultaneously decided to increase the quality and quantity of doctors to address shortages.

AIMS

To evaluate the outcome of innovative medical education at the University of Zimbabwe Medical School.

METHOD

A structured questionnaire was administered to a broad group of staff and student representatives. In addition, a desk review of academic documents and policies and procedures was carried out.

RESULTS

Early patient contact and community attachment which were introduced to the traditional curriculum remained but other teaching methodologies were not sustained with traditional didactic training still taking centre stage with limited staff development and retention. Whilst the annual student enrolment increased from less than 80 to 200 per year the vacancy rate of academic staff increased to 50%.

CONCLUSION

Innovative curricula were partially implemented. The annual student intake increased but the staff complement declined. There is an urgent need to monitor and evaluate outcomes of medical education in Africa to arrest further decline in the quality of health care services.

Prevalence of tobacco use in Eritrea: Results from a noncommunicable disease risk factor survey

The prevalence of noncommunicable diseases in Eritrea is increasing. Tobacco use is a recognized risk factor for most of these diseases, especially cardiovascular disease. No data have been published on tobacco use in Eritrea. The present study sought to establish the prevalence of tobacco smoking in Eritrea. The World Health Organization STEPwise approach was used for the survey, conducted in 2004 on a random national sample size of 2,460 subjects (response rate = 93.7%). The prevalence of tobacco smoking in the general population was 8.1%; the prevalence was 15% among men, compared with 0.6% among women. Prevalence rates were higher in those older than 45 years of age. The prevalence of tobacco smoking was higher among Muslims (11.4%) than Orthodox Christians (5.8%), and among alcohol drinkers (10.2%) than nondrinkers (6.6%). The majority of tobacco users (89.3%) used commercially available cigarettes. A study on knowledge, attitudes, and practices regarding tobacco use is needed to determine the behavioral factors leading to tobacco smoking among the vulnerable groups.

Roll back malaria--an African success story in Eritrea

BACKGROUND

High morbidity and mortality from malaria in Africa prompted the Abuja Declaration by African Heads of State in 2000. The goal set in the declaration for 2010 was to reduce malaria mortality by 50%. Countries were therefore expected to ensure that 60% of people suffering from malaria had access to treatment, that 60% of those at risk received intermittent prophylaxis, and that 60% of people in high-risk groups were using insecticide-treated nets (ITNs) by 2005. In 1999 Eritrea introduced malaria policies, strategies and multi-level interventions targeting households, communities and health facilities.

OBJECTIVES

To assess Eritrea's progress towards meeting the Abuja Declaration goal, targets and key determinants.

METHODS

A retrospective study was undertaken using data from the Health Management Information System (HMIS) and reports of annual reviews. Correlation and regression analysis were used to assess associations between selected variables.

RESULTS

The incidence rate for malaria decreased from 6000/100000 in 1998 to 1100/100000 in 2003, representing > 80% decline in morbidity. The cumulative number of ITNs distributed increased from 50000 in 1998 to 685000 in 2003. The ITN impregnation rate increased from 15% to > 70% during the same period. Indoor residual spraying increased from 7444 kg to 41157 kg of insecticide in 2004 resulting in the protected population increasing from 117017 to 244315 respectively. The number of health workers recruited and trained rose from 936 to 4118. There was a strong correlation between the malaria incidence rate, distribution of ITNs (R2 = 0.76) and the total number of health workers trained (R2 = 0.72). The association was consistent in regression analysis (beta = -0.05, p = 0.03 for ITNs, and beta = -0.249, p = 0.05 for trained health workers).

CONCLUSION

Within 5 years Eritrea met the Abuja Declaration objectives through multiple vector-control methods, case management and surveillance.

A steep decline of malaria morbidity and mortality trends in Eritrea between 2000 and 2004: the effect of combination of control methods

BACKGROUND

Malaria is a huge public health problem in Africa that is responsible for more than one million deaths annually. In line with the Roll Back Malaria initiative and the Abuja Declaration, Eritrea and other African countries have intensified their fight against malaria. This study examines the impact of Eritrea's Roll Back Malaria Programme: 2000-2004 and the effects and possible interactions between the public health interventions in use.

METHODS

This study employed cross-sectional survey to collect data from households, community and health facilities on coverage and usage of Insecticide-Treated Nets (ITNs), Indoor Residual Spraying (IRS), larvicidal activities and malaria case management. Comparative data was obtained from a similar survey carried out in 2001. Data from the Health Management Information System (HMIS) and reports of the annual assessments by the National Malaria Control Programme was used to assess impact. Time series model (ARIMA) was used to assess association.

RESULTS

In the period 2000-2004, approximately 874,000 ITNs were distributed and 13,109 health workers and community health agents were trained on malaria case management. In 2004, approximately 81% households owned at least one net, of which 73% were ITNs and 58.6% of children 0-5 years slept under a net. The proportion of malaria cases managed by community health agents rose from 50% in 1999 to 78% in 2004. IRS coverage increased with the combined amount of DDT and Malathion used rising from 6,444 kg, in 2000 to 43,491 kg, in 2004, increasing the population protected from 117,017 to 259,420. Drug resistance necessitated regimen change to chloroquine plus sulfadoxine-pyrimethamine. During the period, there was a steep decline in malaria morbidity and case fatality by 84% and 40% respectively. Malaria morbidity was strongly correlated to the numbers of ITNs distributed (beta = -0.125, p < 0.005) and the amount (kg) of DDT and Malathion used for IRS (beta = -2.352, p < 0.05). The correlation between malaria case fatality and ITNs, IRS, population protected and annual rainfall was not statistically significant.

CONCLUSION

Eritrea has within 5 years attained key Roll Back Malaria targets. ITNs and IRS contributed most to reducing malaria morbidity.

Continuing communicable disease burden in Eritrea

BACKGROUND AND METHODS

A retrospective study of the national health profile of Eritreans, focusing on acute respiratory tract infection (ARTI), tuberculosis (TB), diarrhoea, sexually transmitted diseases (STDs) and HIV/AIDS, was done on data from 1998 to 2003 through a health information management system. Records were included for patients of all ages receiving outpatient and inpatient hospital services during the study period. All incidence rates were given as cases per 100,000 population.

RESULTS

The incidence of ARTI increased from 6,500 cases per annum in 1998 to 8 500 in 2003, representing a 30% increase. Diarrhoea rates remained unchanged, averaging 3,000 cases. For both ARTI and diarrhoea, rates were at least 3 times higher in children under 5 years of age than in those over 5 years of age. The incidences of TB and STDs decreased from 370 and 220 in 1998 to 170 and 80 in 2003, respectively. HIV/AIDS incidence increased from 40 in 1998 to 65 in 2003, reflecting a 60% increase. The case fatality rates (CFRs) for HIV/AIDS and TB were 12% and 2% in 1998, increasing to 14% and 3%, respectively, in 2001. The CFR for ARTI and diarrhea remained low at 0.3%. CFRs were higher in children under 5 years than in those over 5 years for all the diseases but rates declined consistently, probably reflecting the positive impact of the introduction of the integrated management of childhood illness (IMCI). Although the incidence rate of HIV/AIDS was relatively low compared with rates for TB, ARTI and diarrhoea, the HIV/AIDS CFR was relatively high, posing a threat to the gains made in control of infectious diseases. The disease burden from TB and STDs declined over the 6-year study period, while that from ARTI and HIV/AIDS increased. Consequently the overall disease burden from communicable diseases remained unchanged over the study period.

Prevalence of noncommunicable diseases in Zimbabwe: results from analysis of data from the National Central Registry and Urban Survey

The disease burden from noncommunicable diseases (NCDs) in Africa is rapidly increasing based on projections from a limited number of reports. In the absence of national health surveys in Zimbabwe, all data nationally generated between 1990 and 1997 were analyzed. From 1990 to 1997, prevalence rates (expressed per 100,000 people) of hypertension increased from 1000 to 4000, rates of diabetes increased from 150 to 550, and rates of cerebrovascular accidents (CVA) increased from 5 to 15. The case fatality rate (CFR) for CVA decreased substantially during the period of study, implying improved case management of the disease, while the CFR for most other diseases did not change significantly throughout the study period. The observation of increased prevalence of some NCDs during the study period was corroborated by findings from a blood pressure survey subsequently conducted in an urban environment of Zimbabwe, which revealed a hypertension (blood pressure > or =140/90 mm Hg) prevalence of 35% in women and 24% in men. In spite of the limitations of the centrally generated hospital-based data, its analysis is still valuable. Countries are therefore encouraged to utilize this easily accessible resource for policy formulation and resource mobilization.

Emerging non-communicable disease epidemic in Africa: preventive measures from the WHO Regional Office for Africa

The World Health Organization Regional Office for Africa (WHO AFRO) commissioned a study to compile and analyze published reports on non-communicable diseases (NCDs) in Africa to build evidence on the burden of NCDs in the region. Anecdotally, little information or literature was available on this subject. The objective of the study was to establish the status of NCDs in Africa by using published sources of information. A literature search was done through MEDLINE/PubMed and Google to identify studies that reported on prevalence rates of NCD risk factors. The study confirmed that information on NCDs in Africa was lacking. The prevalence of hypertension was found to be rapidly increasing, from 3% in rural areas to > 30% in some urban settings. In some populations, hypertension prevalence rates were higher in women than in men while the opposite was true in others. Most people with hypertension were not aware of their condition, and of those who were on treatment, < 20% had optimal control. The prevalence of diabetes mirrored that of hypertension, from < 1% in some rural areas to > 20% in some selected populations and racial groupings in urban settings. The predominant type was type 2 diabetes, which accounted for > 80% of all cases in some reports and tended to present later in life. The prevalence of tobacco smoking also varied across the continent, from < 1% in rural women to 50% in some urban men. Recent studies based on analysis of hospital-based information have documented NCD trends that were similar to prevalence data generated from national risk factor surveys. NCD risk factors such as hypertension and diabetes are increasing in Africa.

Prevalence of non-communicable disease risk factors in Eritrea

OBJECTIVE

To establish the baseline prevalence rates for non-communicable disease risk factors in Eritrea.

STUDY DESIGN

A cross-sectional survey was conducted among all the ethnic groups in Eritrea with the WHO STEPwise approach. Hypertension was defined as blood pressure > or = 140/90 mm Hg or a person on medication for hypertension, while diabetes based on medical history of the disease. Of the targeted sample size of 2460, 2352 responded. Respondents were distributed among the six regions of the country proportional to population size. A multistage cluster sampling technique was used. Males and females from 15 to 64 years of age were studied.

MAIN OUTCOME MEASURES

Prevalence rates of hypertension, diabetes mellitus, obesity, smoking, alcohol consumption, physical inactivity, and low vegetable and low fruit consumption.

RESULTS

Prevalence rate of daily smoking of 7.2% with variations among age, sex, religion and regions. A high prevalence of low fruit and low vegetable intake was observed at 84.7% and 50.6% respectively. Alcohol drinking was 39.6%. Level of physical activity was high (90%). The prevalence of obesity was low at 3.3%. The prevalence of hypertension in the general population was 16%, while 2.2% were known diabetic patients. More than 80% of the hypertensive persons were not aware of their condition. No significant rural/urban or sex difference was seen in hypertension prevalence.

CONCLUSION

The baseline data are useful for developing interventions designed to prevent and control NCDs in Eritrea.

The prevalence of hypertension and its relationship with obesity: results from a national blood pressure survey in Eritrea

The prevalence of cardiovascular diseases has been shown to be on the increase in Africa based on hospital-based information and limited national surveys. A recent report on analysis of data from Health Information Management Systems (HIMS) highlighted an increasing burden of noncommunicable diseases (NCDs) in Eritrea, with the incidence of hypertension doubling in a space of 6 years. HMIS data are only a proxy of national prevalence rates, necessitating the conduct of national surveys. The WHO STEPwise approach to surveillance of NCDs was used for the national NCD risk factor survey in 2004. This report focuses on blood pressure (BP) and obesity (body mass index (BMI) > 30 kg/m2) as NCD risk factors in Eritrea. A total of 2352 people in age groups 15 to 64 years participated in the survey. The prevalence of hypertension defined as BP > 140/90 mmHg was 15.9% in the general population, with 16.4% in urban and 14.5% in rural areas, 17% of whom were males while 15% were females. BMI was positively associated with systolic (SBP), diastolic and mean arterial pressure. Although the prevalence of obesity (3.3%) was higher in females, the effect of BMI on BP was higher in males than in females (regression coefficient 0.64 and 0.38, respectively, P < or = 0.05), especially in those >45 years. BMI did not have a significant effect on BP in lean people (BMI < 19) and in those with high BMI, but was positively correlated to SBP in those with normal BMI (P < or = 0.02). BMI and age appear to play a synergistic role in creating a strong association with BP.

Recurrent cholera epidemics in Kano--northern Nigeria

OBJECTIVES

The study examined the factors associated with recurrent cholera epidemics in Kano State of Northern Nigeria, the management of the epidemics and health outcomes.

METHODS

Using epidemiological data from the Public Health Department of the Kano State Ministry of Health, the study examined the frequency and geographical distribution of the epidemics for the period 1995 to 2001; procedures for detection; control measures as well as results of biological and bacteriological testing of water from different sources. Mapping and testing for significance of faecal contamination of water sources were done.

RESULTS

The number of cholera cases in the city was 2 630; 847 and 2 347 in 1995/6, 1997 and 1999 respectively. The State Epidemiological Unit which is responsible for surveillance detected epidemics using set thresholds and activated multi-sectoral emergency responses. Control measures encompassed accurate diagnosis at the reference laboratory, Kaduna; registration of cases; case management and public health measures targeting personal hygiene and water treatment. The cholera epidemics attracted worldwide attention with emergency responses from many agencies including WHO, UNICEF and Medicens Sand Frontiers (MSF). Case fatality rates decreased from 15% in 1995/6 to 5% in 1997 and 2% in 1999. The organism responsible for all the outbreaks was Vibrio cholerae, el-tor of inaba serotype. Water contamination of all sources was the principal cause of the epidemics. There were statistically significant differences in levels of faecal contamination of water sources, wells being most affected, followed by piped water, chi2 = 11.556, (p < 0.02). Bore holes were relatively safer sources of water. Point source epidemics always started from Kano City before fanning out to the rest of the State.

CONCLUSION

Multi-sectoral Epidemic Preparedness and Response (EPR) approaches have contributed to the reduction in case fatality rates over the years and should be sustained. However, in order to prevent future cholera epidemics, there is need to introduce intervention measures that address the root problems of poor sanitation and unsafe water supplies.

Microalbuminuria in urban Zimbabwean women

The prevalence of microalbuminuria (MAU) in African populations has not been reported, nor has the relationship between MAU and hypertension been reported for these populations. We collected spot urine samples from 370 women, 25 years and older as a part of a population-based, cross-sectional blood pressure survey in an urban community in Zimbabwe and analysed the samples for albumin and beta2-microglobulin. The age-adjusted prevalence of hypertension was 30% for women 25 years and older in this community. After excluding the samples with hematuria (11%), the prevalence of MAU (3.0 < or = albumin-to-creatinine ratio (ACR, mg/mmol) <25.0) in the study population was 9%. When age-adjusted to the population in the community, the prevalence was 8% among women 25 years and older. The prevalence of MAU was substantially higher in hypertensive (HT) than in normotensive (NT) women (16% vs 4%, P<0.001). A significantly higher level of log ACR in HT was found in each age group except the youngest age group (age 25-34). In age-adjusted multiple regression, percent fat mass was negatively associated with log ACR (beta = -1. 18, 95% CI (-0.23, -2.21), P = 0.02). In a similar regression analysis, higher log beta8-microglobulin-to-creatinine ratio was very strongly associated with higher log ACR (beta = 0.34, 95% CI (0.25, 0.43), P<0.0001) and significantly associated with lower percent fat mass (beta = -1.02, 95% CI (-0.25, -1.8), P = 0.01). These results suggest that MAU is frequently caused by hypertension, but that other diseases may contribute to its presence.

Economic development and women's blood pressure: field evidence from rural Mashonaland, Zimbabwe

A survey of 515 non-pregnant women at 12 geographically chosen research sites in rural Mashonaland shows significant differences in mean blood pressure, controlled by age cohorts. Three levels of economic development are identified: (1) the traditional economy on communal lands, with lowest blood pressure, (2) the wage economy in areas of large-scale commercial agriculture, with elevated blood pressure and (3) the wage economy in mining areas, with the highest elevation of blood pressure. The area is dominated by the primate city, Harare, up to distances of 300 km and beyond, from which forces of change and modernization emanate. It is seen that potassium, sodium and the sodium potassium ratio, are distance-related to Harare and that women's blood pressures tend to follow suit. The rise of body sodium in young persons at risk, often accompanied by declining potassium intake and other changes of modernization, suggest that more attention should be focused on rural areas in Africa, now in the throes of economic change.

Correlates of blood pressure in an urban Zimbabwean population and comparison to other populations of African origin

We have evaluated the relationship between systolic blood pressure (SBP) and age, body mass index (BMI), waist circumference, sodium to potassium ratio (Na/K), and tobacco use in an urban African population. We conducted a random, population-based, cross-sectional survey of people 25 years and older in Marondera, Zimbabwe, with over-sampling in older age groups (n = 775), using a method comparable to that used in International Collaborative Study on Hypertension in Blacks (ICSHIB). The age-adjusted prevalences of hypertension in Marondera (SBP >/=140/DBP >/=90/antihypertensive medication) were 30% for women and 21% for men. The average BMI was 26.3 kg/m2 for women and 21.4 kg/m2 for men. The prevalence of hypertension had a steep association with age and in women ranged from 15% (25-34 years) to 63% (55 years and over) and in men from 9% to 47%. No tobacco use in women and greater Na/K ratio in spot urines in men were significantly associated with an increased SBP. In both men and women the levels of hypertension and SBP were strongly positively associated with BMI, although the relationship appeared to plateau in women with a BMI greater than >/=25 kg/m2. At a given BMI, men and women had similar SBPs and prevalences of hypertension. There is a very high prevalence of hypertension among urban Zimbabweans, particularly among women. Under the assumption the studies are comparable, the prevalence of hypertension in Zimbabwean women (41%) and men (26%) after age adjustment to the ICSHIB populations, appeared higher than almost all of the ICSHIB populations, including those with higher average body mass indexes. Journal of Human Hypertension (2000) 14, 65-73.

Lung function of Zimbabwean farm workers exposed to flue curing and stacking of tobacco leaves

OBJECTIVES

To perform lung function tests on tobacco farm workers (TFWs) chronically exposed to flue curing and stacking of tobacco leaves and to compare them with vegetable farm workers (VFWs) who were not exposed to any known air pollutant (control).

DESIGN

Comparative study.

SETTING

Tobacco and vegetable farms.

SUBJECTS

20 TFWs and 30 VFWs. All subjects were male and the mean age, height and weight of the two groups were not significantly different.

OUTCOME MEASURES

Lung function indices.

RESULTS

Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow rate (PEFR) of the TFWs were 3.28 +/- 0.51 litres, 2.68 +/- 0.74 litres and 6.41 +/- 2.08 litres/second, respectively. These figures were significantly lower than 3.97 +/- 0.83 litres, 3.09 +/- 0.71 litres and 8.62 +/- 2.74 litres/second, respectively, for the control subjects (P < 0.01, 0.05 and 0.01, respectively). However, mean FEV1 as a percentage of the FVC (FEV1%) of the TFWs was not significantly different from that of the controls FVC of the TFWs declined with duration of service (r = 0.74; P < 0.01).

CONCLUSION

The results are indicative of restrictive lung defect in the TFWs and may be attributed to long-term exposure to flue curing and stacking of tobacco leaves. The results also suggest the importance of the duration of exposure in the aetiology of lung impairment in this environment.

Salt sensitivity is not associated with hyperinsulinaemia in a sample of rural black Zimbabweans

OBJECTIVES

To investigate the relationship between salt sensitivity and hyperinsulinaemia in rural black African subjects.

DESIGN

An intervention study where 27 subjects were divided into two groups; group 1 was initially salt loaded (300 mmol Na+/day), while group 2 was salt restricted (25 mmol Na+/day), each for 4 days, after which a cross-over study was done.

SETTING

Chidamoyo, a rural area 383 km north of Harare, Zimbabwe.

SUBJECTS

Twenty-seven rural volunteers (16 women, 11 men).

OUTCOME MEASURES

Systolic and diastolic blood pressures, salt sensitivity, insulin and glucose levels, body mass index and mean arterial pressure.

RESULTS

Mean arterial pressure, which was 91 +/- 2 mmHg on a low-salt diet, increased significantly (P < 0.01) to 105 +/- 3 mmHg on high-salt diet in the salt-sensitive subjects. In the same salt-sensitive subjects, the fasting insulin level was 8.4 +/- 0.8 microU/ml on a low-salt and 6.1 +/- 1.0 microU/ml on a high-salt diet. The difference was not statistically significant.

CONCLUSIONS

Although salt pressor sensitivity was demonstrated in the subjects, there was no accompanying increase but rather a decrease in fasting insulin levels, suggesting that in the short term, salt sensitivity and hyperinsulinaemia are not linked in raising blood pressure in this sample of rural Zimbabwean subjects.

Effect of variation in environmental temperature on blood pressure: is it important?

OBJECTIVES

To study the effect of variation in environmental temperature on blood pressure and pulse.

DESIGN

Repeated blood pressure and pulse measurements in volunteers on two days when environmental temperatures differed by 10 degrees C.

SETTING

Part of an ongoing community based study.

SUBJECTS

25 Black subjects (23 males and two females) volunteered from a population cohort participating in an ongoing longitudinal study examining cardiovascular risk factors in an urban African Black environment.

MAIN OUTCOME MEASURE

Mean systolic and diastolic blood pressures and pulse rates.

RESULTS

The systolic and diastolic blood pressures were significantly higher when recorded at 15 degrees C than at 25 degrees C, mean difference 32.2 +/- 4.2, p < 0.001 and 19.5 +/- 3.0 p < 0.001) for systolic and diastolic blood pressures respectively. The pulse rate per minute at 15 degrees C was significantly lower than at 25 degrees C (mean difference 11.1 +/- 3.2 p = 0.002).

CONCLUSIONS

A decrease in environmental temperature by 10 degrees C appears to increase blood pressure. Awareness of this phenomenon is important, especially when surprisingly high blood pressures are observed during low ambient temperatures, to avoid over diagnosis of hypertension. This phenomenon, together with that already established of the white coat hypertension, may lead to the erroneous diagnosis of hypertension.

Relationship between blood pressure and body mass index in lean populations

Associations between body mass index (BMI) and blood pressure (BP) have been consistently observed, but remain poorly understood. One unresolved question is whether there is a linear relationship across the entire BMI range. We investigated this question among 11,235 adult men and women from seven low-BMI populations in Africa and the Caribbean. We used kernel smoothing and multivariate linear and spline regression modeling to examine gender differences in the relationship and to test for a threshold. Age-adjusted slopes of BP on BMI were uniformly higher in men than women, with pooled slope ratios of 2.00 and 2.20 for systolic and diastolic BPs, respectively. Men displayed no evidence of age modification or nonlinearity in the relationship, and the age-adjusted slope of systolic BP on BMI was 0.90 (95% confidence interval [CI], 0.76 to 1.04). Women demonstrated both age modification and nonlinearity. For both younger (<45 years) and older (45+ years) women, the optimal change point for a single threshold model was found to be 21 kg/m2. Slopes of systolic BP on BMI above this threshold were positive and significant: 0.68 (95% CI, 0.54 to 0.81) and 0.53 (95% CI, 0.29 to 0.76) for younger and older women, respectively. Slopes below the threshold were essentially zero for both groups of women, and the difference between the slopes above and below the threshold was significant for younger women (P=.019). In summary, we observed a threshold at 21 kg/m2 in the relationship between BMI and BP for women but not for men. This contributes to the effort to identify the mechanisms that underlie this relationship and how they differ by gender.

Comparison of the Omron HEM-713C automated blood pressure monitor with a standard ausculatory method using a mercury manometer

OBJECTIVES

To compare the Omron HEM-713C automated blood pressure machine with the standard ausculatory method using a mercury manometer.

DESIGN

Blood pressures of randomly selected subjects were measured using both the Omron HEM-713C and the mercury manometer.

SETTING

Dombotombo surburb in Marondera, Zimbabwe.

SUBJECTS

One hundred and sixteen subjects 25 years and above (47 males and 69 females) randomly selected in Marondera.

MAIN OUTCOME MEASURE

Systolic blood pressure and diastolic blood pressure.

RESULTS

The Omron HEM-713C passed with a grade B for both systolic and diastolic blood pressures when using the British Hypertension Society protocol. It also passed both systolic and diastolic criteria for Association of the Advancement of Medical Instrumentation.

CONCLUSION

The Omron HEM-713C compares well with the standard mercury manometer, we therefore recommend its use in both research and clinical applications which require blood pressure measurements.

Ethnic differences of renin-sodium profile and renal prostaglandins in the pathogenesis of systemic arterial hypertension

OBJECTIVE

To compare renin-sodium profile and renal prostaglandins (PGs) of Black normotensive and hypertensive patients, with the same parameters of Caucasian normotensives and hypertensives, e.g. to reveal some of the ethnic differences in the pathogenesis of systemic (essential) hypertension.

SUBJECTS

27 Black Zimbabwean normotensive and 27 hypertensive patients were matched by age, sex and number to Caucasian normotensives and hypertensives (systolic blood pressure > 160 mm Hg or diastolic blood pressure > 95 mm Hg, or both). All were examined during two protocols producing sodium depletion (less than 40 mmol sodium diet/day) for five days, followed by sodium loading (300 mmol sodium diet/day) for another five days. Changes in plasma renin activity (PRA), urinary aldosterone (Aldo), prostaglandin E2(PGE2) and prostaglandin F2 alpha (PGF2 alpha) excretions were simultaneously assessed by radioimmunoassay.

RESULTS

Compared to caucasians the Blacks showed similar basal aldosterone and Na+ excretion but significant Na+ retention (30pc) during Na+ loading. Their basal PRA was lower (32pc) and poorly responding to sodium depletion/loading. They had suppressed PG synthesis, the PGE2/PGF2 ratio being significantly decreased 11pc. Renin profiles, obtained by plotting PRA against urinary Na+ excretion showed prevalence of low renin hypertension (62pc) in Black patients. All Caucasian patients had normal renin hypertension. At basal level the Black hypertensives had suppressed synthesis of vasodilator PGF2/PGF2 alpha ratio by 32pc. This finding was in accordance with their low renin hypertension. During sodium depletion the PGs excretion was increased in both hypertensive groups. The opposite effect was found during sodium loading.

CONCLUSION

This study shows ethnic differences in renin-sodium profile and renal PG synthesis, during changes in dietary sodium. It addresses an old medical controversy about the usefulness of renin profiling in identifying hypertensive patients who are at increased risk for heart attack (Whites with normal/high renin hypertension) or increased risk of stroke (Blacks with low renin, sodium mediated hypertension).

Prevalence of hypertension among women in rural Zimbabwe: a comparison of pregnant and non-pregnant women

OBJECTIVES

To determine the prevalence of pregnancy induced hypertension (PIH) in rural Zimbabwe.

DESIGNS

A blood pressure survey conducted in three socio-economic strata of rural Zimbabwe, communal lands, commercial farms and mining areas.

SETTING

Rural Zimbabwe, Mashonaland West Province.

SUBJECTS

627 pregnant (> 20 weeks gestation) and 483 non pregnant (ages 16 to 45) women.

MAIN OUTCOME MEASURE

Prevalence of PIH.

RESULTS

PIH was defined in two ways: 1. A combination of > or = 2+ proteinuria and systolic and/or diastolic pressure > or = SD above the mean for all pregnant women (> or = 123/75 mmHg). 2. > or = 1+ proteinuria and blood pressure of 140 and/or 90 mmHg. Eight women met definition 1 and seven met definition 2, giving a prevalence of 0.8pc; 1.3pc and 3.2pc in communal lands, commercial farms and mines respectively. In non-pregnant women the prevalence of hypertension (> or = 160 and/or 95 mmHg) was 3.5pc; 5.4pc and 15.1pc in communal lands, commercial farms and mines respectively.

CONCLUSION

PIH is rare in rural Zimbabwe. Hypertension among non-pregnant women of child bearing age is most common in mining communities which have many similarities to urban environments.

Renin-sodium profile and renal prostaglandins in the pathogenesis of systemic arterial hypertension in blacks

Thirteen black women with systemic (essential) arterial hypertension, age-matched with normotensives, were examined during two protocols inducing sodium depletion and sodium loading respectively. Changes in plasma renin activity (PRA), urinary aldosterone values and prostaglandin E2 (PGE2) and F2a (PGF2a) excretion were simultaneously assessed. Renin profiles, obtained by the plotting of PRA against the urinary excretion of sodium, showed a 62% prevalence of low-renin hypertension, the remaining 38% of the patients having normal-renin hypertension. At basal level the hypertensives had suppressed renal synthesis of vasodilator PGE2 and a non-significant increase in venopressor PGF2a. This was reflected in the significant 32% decrease in the PGE2/PGF2a ratio. This finding was in keeping with their low-renin hypertension. During sodium depletion PG excretion was increased in both normotensive and hypertensive groups. The opposite effect was found during sodium loading. The results of this study do not support a natriuretic role for renal PGE2, but do support the hypothesis that there is decreased renal vasodepressor PGE2 synthesis in black hypertensive patients.

Factor VII, antithrombin III, leukocyte and platelet counts in a sample of black and white Zimbabwean blood donors

Studies in Southern Africa have shown that whites have significantly greater morbidity and mortality from coronary heart disease than blacks. This study investigated the distribution of some haemostatic variables known or suspected to be correlated with greater risk for coronary heart disease in healthy black and white Zimbabwean men. Factor VII, antithrombin III, leukocyte and platelet counts were measured in 56 blacks and 29 whites aged between 20 and 50 years. We found significantly greater factor VII and leukocyte counts in the whites compared to the blacks. The other variables measured were similar in the two ethnic groups. These results suggest that the greater prevalence of coronary heart disease in whites is consistent with high levels of factor VII and white blood cell counts previously identified as risk factors for this condition.

Aspects of insulin resistance in urbanisation-related hypertension in Zimbabwe: a preliminary report

Insulin resistance has been associated with essential hypertension, obesity and old age. Likewise high blood pressure has been observed to develop in some rural people who migrate to urban areas in developing countries like Zimbabwe. The pathogenesis of this urbanisation-related hypertension is still unknown. We therefore investigated aspects of insulin resistance in urbanisation-related hypertension in Zimbabwean blacks using oral glucose tolerance tests. Thirty normotensive subjects and 30 newly diagnosed hypertensive patients participated in this study. All subjects had blood pressures measured by random zero sphygmomanometry. Fasting blood samples were taken before a 75 g oral glucose load was given. Four other blood samples were subsequently collected at 30 minute intervals and determination of blood glucose and insulin levels was made. Fasting glucose (mmol/l) and fasting insulin (in microU/ml) levels were, respectively, 4.8 +/- 0.2 and 19 +/- 2 in hypertensive patients which were significantly higher than 4.0 +/- 0.2 and 13 +/- 1.6 in normotensive patients (P < 0.05). In addition the area under the insulin curve was significantly higher in hypertensive than in normotensive patients (P < 0.05). These findings suggest that insulin resistance may play a role in urbanisation-related hypertension.

Platelet activity and salt sensitivity in the pathogenesis of systemic (essential) hypertension in black Africans

Black essential hypertensive patients with a mean arterial pressure of 125 +/- 3 mm Hg (mean +/- SEM), and age and sex matched normotensive subjects with a mean arterial pressure of 89 +/- 2 mm Hg were studied under baseline conditions, after five days of salt restriction and after five days of salt loading. Salt sensitivity was defined as an increase of mean blood pressure exceeding 5% when progressing from low to high sodium intake. In vitro platelet responsiveness was assessed by aggregometry, and in vitro platelet activity by estimation of beta-thromboglobulin (BTG) in plasma and thromboxane B2 (TXB2) excretion rate. Salt sensitivity was present in 66% of hypertensive and 55% of the normotensive subjects. An increased platelet aggregability to ADP (25%), to epinephrine (34%) and to collagen (12%) was found in parallel with an increased in vivo platelet activity (BTG increased by 55% and TXB2 by 18%) in the hypertensives. All changes were significantly exaggerated in the salt sensitive as compared to salt resistant hypertensive patients.

Pathophysiological mechanisms of urbanisation-related hypertension and the sodium pressor response in black Zimbabweans

This study examined the role of endothelin (ET), the thromboxane A2 (TXA2)-prostacyclin (PGI2) ratio (TXA2/PGI2), plasma renin activity (PRA) and urinary aldosterone excretion (ALDO) in urban hypertensive patients and in the sodium pressor response in normotensives. Twenty-seven urban hypertensive patients and the same number of normotensive controls were studied on baseline diet, after 5 days of sodium restriction and after 5 days of sodium loading. Mean arterial blood pressure, plasma and ET values, PRA, TXA2/PGI2 and ALDO were assessed on each diet. The results showed that baseline PRA was suppressed in the hypertensive patients; this indicates that urbanisation-related hypertension is of the low renin type. ET levels and TXA2/PGI2 were higher in hypertensive than in normotensive subjects, suggesting an association between high blood pressure and these factors. Although the baseline PRA in hypertensives was suppressed, urinary ALDO was no different from that in the normotensive controls where PRA was normal. In addition, sodium restriction did not increase PRA in hypertensive subjects while it more than doubled it in the controls. However, ALDO in hypertensive patients increased to levels that were no different from those in the normotensive subjects. Sodium loading increased blood pressure, ET values and TXA2/PGI2 indicating an association between the latter two factors and the sodium pressor response in those with hypertension. ALDO decreased to similar levels on sodium loading in the two groups. This decrease in ALDO was accompanied by suppression of PRA only in normotensive subjects. In conclusion, the low-renin-activity urban hypertensives we studied had increased baseline ET levels and TXA2/PGI2.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma fibrinogen levels, leucocyte and platelet counts in male Zimbabwean hypertensives

Plasma fibrinogen levels, leucocytes and platelets are among the many factors known to influence haemostasis. Impaired haemostatic processes in hypertension are thought to contribute to the other cardiovascular diseases seen in this condition. This study compares the level of plasma fibrinogen, and leucocyte and platelet counts between 17 male hypertensives and 24 male normotensives. The results for the hypertensives were: leucocyte count mean 5.45 x 10(9)/L, platelet count mean 234.7 x 10(9)/L, and plasma fibrinogen 4.13 g/L. The results for the normotensives were: leucocyte count mean 4.83 x 10(9)/L, platelet count mean 222.9 x 10(9)/L, and plasma fibrinogen 3.27 g/L. The hypertensives had higher plasma fibrinogen levels, and leucocyte and platelet counts compared to the normotensives, but this only reached statistical significance for the plasma fibrinogen levels (p < 0.025).

Blood pressure response to acute changes in dietary sodium in young Zimbabwean men

OBJECTIVE

The primary objective of this study was to determine the effect of acute alterations in sodium intake upon the blood pressure and hormone levels of young Zimbabwean men.

DESIGN

Blood pressure, 24-h urinary electrolyte excretion and plasma concentrations of angiotensin II, aldosterone, and atrial natriuretic peptide were measured in normotensive black medical students. Three sets of measurements were taken: (1) during free access to sodium (baseline); (2) after 4 days on a low-sodium diet (10 mmol/day); and (3) after 4 days on a high-sodium diet (800 mmol/day).

METHODS

Blood pressure was measured by random zero sphygmomanometry, hormone levels by radioimmunoassay, and urinary electrolytes by flame photometry.

RESULTS

The low-sodium diet caused the range of pulse pressure to narrow, with a decrease in systolic blood pressure (SBP) and an increase in diastolic blood pressure (DBP). With the introduction of the high-sodium diet, SBP increased and DBP decreased. Mean arterial pressure did not change. At the same time, angiotensin II and aldosterone decreased. Plasma atrial natriuretic peptide did not change. A subgroup of the men on the high-sodium diet also received 100 mmol potassium/day. The increase in SBP associated with high sodium was significantly attenuated by the presence of added potassium.

CONCLUSIONS

SBP of young black Zimbabwean men is lowered by dietary sodium restriction and rises with a large increase in dietary sodium for a short duration, but mean arterial pressure does not change due to the opposing decreases in DBP.

Pathogenesis of systemic (essential) hypertension in Zimbabwean hypertensive patients. I. Humoral factors

Twenty-seven male and female black Zimbabweans hypertensive patients were matched by age and sex and compared to 27 normotensive subjects. All subjects were examined after dietary sodium depletion, followed by sodium loading. In addition to renin status and salt-sensitivity, urine aldosterone, renal prostaglandins, plasma atrial natriuretic peptide (ANP) and plasma endothelin were assessed. The following ethnic characteristics for Zimbabwean essential hypertensive patients were found: increased prevalence of salt-sensitive hypertension (66 pc); hyporesponsive renin-angiotensin system after contraction of circulating plasma volume; higher prevalence of low-renin hypertension (59 pc); suppressed renal prostaglandins, especially in low-renin hypertensives, suggesting suppression or deficit of renal kallikrein-kinin system; increased levels of ANP in low-renin hypertensive patients. Plasma endothelin was comparably increased in both normal- and low-renin hypertensive patients.