Biomedical subjects

R Wilks

Publications and source records attributed to R Wilks.

At least 37 records · Page 2Linked to original sources

PubMed2000

Underreporting of energy intake in four populations of African origin.

OBJECTIVE: To investigate the frequency of dietary underreporting in four African populations in different geographic and cultural settings. SUBJECTS: Seven-hundred and forty three men and women from rural Cameroon, 1042 men and women from urban Cameroon, 857 men and women from Jamaica and 243 male and female African Caribbeans from the UK. Subjects who reported dieting or weight control were excluded. MEASUREMENTS: Habitual dietary intake was estimated with a quantitative food frequency questionnaire, developed specifically for each country. Underreporting was defined using three cut-off levels for energy intake/estimated basic metabolic rate (EI/BMRest), based on age, sex and weight, in each site. RESULTS: The EI/BMRest was highest in rural Cameroonian men at 3.07 (95% confidence interval: 2.97, 3.17) and women at 2.84 (2.74, 2.94), intermediate in urban Cameroon and Jamaica and lowest in the UK men and women at 1.44 (1.26, 1.62) and 1.41 (1.21, 1.61). This trend existed even after adjustment for age, BMI and education (P for trend<0.0001). The trend in the frequency of underreporting using the lowest cut-off level for EI/BMRest of 1.15 was 6% and 6% in rural Cameroon for women and men, respectively, 4% and 5% in urban Cameroon, 24% and 19% in Jamaica and 28% and 39% in the UK. With higher cut off levels this trend was similar. CONCLUSION: The results suggest that the frequency of dietary underreporting differs between societies and that Westernization may be one of the factors underlying this phenomenon.

Adult↗

PubMed2000

Profile of uncontrolled hypertensive patients attending the Specialist Hypertension Clinic, University Hospital of the West Indies.

The purpose of this study was to describe the knowledge of hypertension, its management, anthropometric measurements, blood pressure (BP), medication use, and current lifestyles of patients with persistent hypertension. Patients (n = 80) attending the Specialist Hypertension Clinic at the University Hospital of the West Indies (UHWI) who had a baseline systolic BP > 140 mmHg and/or a diastolic BP > 90 mmHg were invited to participate in the study. Blood pressure, height, weight, waist and hip circumferences were measured. Body mass index (BMI) and waist/hip ratio (WHR) were calculated. A pretested questionnaire with 40 items eliciting demographic data, level of activity, dietary habits, knowledge of hypertension, medication compliance, use of alternative medicines, and substance use was administered to each participant. Mean BMI for men was 27.65 (95% CI 25.7-29.6); mean BMI for women was 30.89 (95% CI 26.1-35.7). In men, there was an association between BMI and WHR, r = 0.62, p < 0.05, an association between BMI and diastolic BP and a negative association between BMI and activity level (r = -0.42, p < 0.05). There was also an association between systolic BP and substance use (r = 0.41, p < 0.05). Although the majority of both men and women were classified as obese, only 12% of men and 7% of women recognized diet and overweight as contributing to high blood pressure. Reported diets tended to be high in fat, salt and meats and low in vegetables and fruits; the majority of the participants were sedentary. Medication compliance was good, with a mean of only four days of medications missed per month. These findings suggest that to lower blood pressures in this population, the use of nonpharmacologic therapy involving lifestyle changes such as improved diet, weight loss and increased physical activity will be important.

Anthropometry↗

PubMed2000

Quality of care of hypertension in three clinical settings in Jamaica.

To determine quality of monitoring and control of hypertension in Jamaica, 756 records of patients, aged > 30 years, attending a public general clinic (PUBMC) (n = 500), a specialist hypertension clinic (SPMC) (n = 119) and a private group general clinic (PRMC) (n = 137), for more than one year, were reviewed. Duration of follow-up varied among clinics with the longest mean follow-up at PRMC (10.8 yrs) compared to 6.1 years and 4.7 years at the PUBMC and SPMC respectively. Mean age was greatest at the PUBMC (60 yrs) compared to 53 years in the SPMC and 50 years in the PRMC (p < 0.001). Sex distribution differed among clinics with 15% men in the PUBMC, 34% in the SPMC and 54% in the PRMC (p < 0.001). Over 92% of patients had blood pressure (BP) recorded at least once in the 12-month review period. Hypertension was defined as being prescribed antihypertensive medication in clinic records. By this definition 98% SPMC patients were hypertensive, compared to 87% PUBMC and 80% PRMC. Using BP < 160/95 mmHg, the PRMC control rate, 63% was significantly better than those of PUBMC (46%) and SPMC (49%) (p < 0.01). The odds ratio and 95% confidence interval for poor control (BP > 160/95 mmHg) at the PRMC was 0.57 (0.34-0.97) compared to the other two clinics after adjustments for age, clinic type, duration of follow-up and gender. Only age was a significant covariate with older patients at greater risk of poor control. Only 18% of hypertensives were controlled to BP < 140/90 mmHg with no difference among clinics. Diuretics were the commonest agent used at the PUBMC (76%) and SPMC (86%) followed by alpha-methyldopa, 41% and 27%, respectively. These agents were less commonly prescribed at the PRMC than at the other clinics (45% diuretics and 8% alpha-methyldopa, p < 0.001 for both agents compared to other clinics). PRMC used more angiotensin converting enzyme inhibitors 38%, compared to SPMC 23% and PUBMC 1% (p < 0.001). Between 9% and 15% of patients at the PUBMC and PRMC had recorded data on smoking and alcohol use compared to 69% at the SPMC. A record of body weight was found in 99% at SPMC compared to 82% at PRMC and 33% at PUBMC (p < 0.001). Surveillance for complications differed for proteinuria (PRMC 33%, PUBMC 15%, SPMC 15%) and fundoscopy (PUBMC 0%, PRMC 3%, SPMC 43%). These results show very limited adherence to recommended hypertension treatment guidelines in all three settings.

Adult↗

PubMed2000

Impact on blood pressure control of a six-month intervention project.

The aim of this study is to evaluate the impact of a six-month structured education programme on blood pressure (BP) control in patients with uncontrolled hypertension. All patients attending the Specialist Hypertension Clinic, University Hospital of the West Indies (UHWI), between January 4 and March 29, 1999, with blood pressure > 140/90 mmHg (n = 80), were randomly divided into Group 1, cases (n = 42) and Group 2, controls (n = 38). A 40-item pretested questionnaire, administered at the baseline and final visits of both groups, elicited demographic, lifestyle and knowledge data. Group 1 attended monthly structured interventions for six months. Except for diastolic blood pressure among male controls, diastolic blood pressure and systolic blood pressure were significantly reduced at the end of the intervention period (p < 0.01). Knowledge improved among the male patients (p < 0.01). Among the female patients, activity scores were significantly increased (p < 0.01), weight (p < 0.05) and BMI (p < 0.05) were significantly reduced. There were no differences in these variables among the controls. This intervention had a benefit in blood pressure control.

Adult↗

PubMed2000

The use of herbal teas and remedies in Jamaica.

We investigated the prevalence of the use of herbs among adults and children in Jamaica in 1996. Two concurrent surveys were conducted in randomly selected urban and rural areas: among adults and among caretakers of young children. From over 90% of the selected households, all caretakers of children under 6 years and one randomly selected adult (18 years or older) were interviewed using structured questionnaires. The 457 adults reportedly used 156 types of herbs: a mean of 6 +/- 3 (mean +/- standard deviation) by the urban adults, and 10 +/- 6 by the rural adults (t-test, p < 0.001). Almost 100% of respondents had at some time used herbs for teas or for treating illnesses. The most common method of preparation was by infusion or boiling in water, then adding sugar. Urban respondents, women and those who were employed were more likely to buy medicines than to use herbal remedies. One hundred and sixty-seven caretakers of 203 children under 6 years were interviewed. The mean number of herbs given to each child was between 2 and 3. The most common herbs were introduced within the first 6 months of life. Many caretaker factors were associated with herbal use. Public health implications include the potential toxicity of some herbs, the possibility that herbal teas given to young children may displace more nutritious foods and delay presentation to health care facilities. The findings will allow policy makers to target those most likely to use herbal preparations or to give them to young children, and target herbs to be analyzed for toxic or beneficial properties.

Adolescent↗

PubMed1999

Diabetes in the Caribbean: results of a population survey from Spanish Town, Jamaica.

AIMS: To characterize the prevalence of diabetes and associated risk attributes in the Jamaican population. METHODS: A random population sample was recruited by door-to-door canvassing (n = 1303). A final participation of 60% was achieved. Oral glucose tolerance testing was conducted after an overnight fast and standard anthropometric and demographic data were collected. RESULTS: The prevalence of Type 2 diabetes mellitus was 9.8% (95% confidence interval (CI) 7.2-12.4) among men and 15.7% (95% CI 13.1-18.3) among women with an overall prevalence of 13.4% (95% CI 11.5-15.2). Impaired glucose tolerance was found among 12.3% of men and 14.7% of women. The sex patterns were consistent with a fourfold excess of obesity in women compared to men. The odds ratios for diabetes, fourth vs. first quartiles were 5.42 (95% CI 2.02-16.88) in men and 3.32 (95% CI 1.73-6.63) in women for body mass index (BMI) and 17.39 (95% CI 3.86-78.27) in men and 5.48 (95% CI 2.84-11.00) in women for WHR in a logistic model controlling for age. The population attributes risk percentage, for diabetes, of being overweight and having waist-to-hip ratio (WHR) greater than the median (0.80) were 66% and 80%, respectively. The contribution of central obesity, as characterized by WHR, was also significant in sex-specific multivariate models that included age and BMI. Prevalent hypertension and family history of diabetes were likewise associated with increased odds of having the disease. CONCLUSIONS: The prevalence of diabetes in Jamaica now exceeds that observed among European-origin populations and reflects the emerging epidemic of obesity. The excess risk for this population could not be attributed entirely to relative weight. The pronounced sexual dimorphism in diabetes prevalence most likely reflects the substantial excess of obesity among women compared to men. Like many other island nations, Caribbean societies now appear to be at substantial risk of diabetes.

Aged↗

PubMed1999

Standardized comparison of glucose intolerance in west African-origin populations of rural and urban Cameroon, Jamaica, and Caribbean migrants to Britain.

OBJECTIVE: To compare the prevalence of glucose intolerance in genetically similar African-origin populations within Cameroon and from Jamaica and Britain. RESEARCH DESIGN AND METHODS: Subjects studied were from rural and urban Cameroon or from Jamaica, or were Caribbean migrants, mainly Jamaican, living in Manchester, England. Sampling bases included a local census of adults aged 25-74 years in Cameroon, districts statistically representative in Jamaica, and population registers in Manchester. African-Caribbean ethnicity required three grandparents of this ethnicity. Diabetes was defined by the World Health Organization (WHO) 1985 criteria using a 75-g oral glucose tolerance test (2-h > or = 11.1 mmol/l or hypoglycemic treatment) and by the new American Diabetes Association criteria (fasting glucose > or = 7.0 mmol/l or hypoglycemic treatment). RESULTS: For men, mean BMIs were greatest in urban Cameroon and Manchester (25-27 kg/m2); in women, these were similarly high in urban Cameroon and Jamaica and highest in Manchester (27-28 kg/m2). The age-standardized diabetes prevalence using WHO criteria was 0.8% in rural Cameroon, 2.0% in urban Cameroon, 8.5% in Jamaica, and 14.6% in Manchester, with no difference between sexes (men: 1.1%, 1.0%, 6.5%, 15.3%, women: 0.5%, 2.8%, 10.6%, 14.0%), all tests for trend P < 0.001. Impaired glucose tolerance was more frequent in Jamaica. CONCLUSIONS: The transition in glucose intolerance from Cameroon to Jamaica and Britain suggests that environment determines diabetes prevalence in these populations of similar genetic origin.

Adult↗

PubMed1999

A comparative study of pregnancy outcome in teenage girls and mature women.

The objective was to compare the pregnancy outcome of teenage girls and mature women. The design was a retrospective study of births from January to December 1990, based on the antenatal clinic and the labour ward, University Hospital of the West Indies, Jamaica. Teenage mothers, 13 to 19 years old, and a control group of mothers, 22 to 23 years old, were selected from the records of 2,394 live, singleton births between 200 and 305 days' gestation. The main outcome measures were birth weight, crown heel length, head circumference, head circumference:length ratio, ponderal index and placental weight. The results showed that in the teenage group, weight, body mass index at booking, haemoglobin concentration in each trimester, and minimum haemoglobin level during pregnancy were lower than in the control group. Systolic blood pressure in the first and the second trimesters was lower than in controls, but there was no significant difference in the third trimester nor in the delivery systolic blood pressure. Babies of teenage mothers had lower birth weights and smaller head circumferences than the babies of the control group, but there was no significant difference between the groups in crown heel length, ponderal index, head circumference:length ratio, and placental weight. These data support the hypothesis that teenaged girls are not physically mature and, as a consequence, their offspring have lower birth weights and smaller head circumferences.

Adolescent↗

PubMed1998

Human leukocyte antigen class II alleles associated with human T-cell lymphotropic virus type I infection and adult T-cell leukemia/lymphoma in a Black population.

BACKGROUND: Human T-cell lymphotropic virus type I (HTLV-I) is linked to adult T-cell leukemia/lymphoma (ATL) and HTLV-I-associated myelopathy (HAM; also known as tropical spastic paraparesis [TSP]), a chronic neurodegenerative disorder. Worldwide, several million HTLV-I carriers are at risk for disease, with an estimated lifetime cumulative risk of 1%-5%. However, the determinants of disease progression are relatively unknown. We studied human leukocyte antigens (HLA class II) that have been implicated in the pathogenesis of HTLV-I-related diseases. METHODS: We analyzed HLA class II alleles among asymptomatic HTLV-I carriers (n = 45), patients with ATL (n = 49) or HAM/TSP (n = 54), and HTLV-I seronegative control subjects (n = 51). All participants were of African descent and were enrolled in epidemiologic studies conducted at the University of the West Indies, Kingston, Jamaica. We used standard microlymphocytotoxicity assays for HLA antigen serotyping and polymerase chain reaction-based methods to examine HLA class II DRB1 and DQB1 alleles. RESULTS: Two antigens determined by serotyping, DR15 and DQ1, occurred at significantly increased frequency among HTLV-I carriers compared with seronegative control subjects (42% versus 22% for DR15 [odds ratio [OR] = 2.7; 95% confidence interval [CI] = 1.0-7.2] and 78% versus 53% for DQ1 [OR = 3.1; 95% CI = 1.2-8.5]). Asymptomatic carriers were shown to have an HLA class II allele distribution similar to that of patients with ATL, and the frequencies of the alleles DRB1*1501, DRB1*1101, and DQB1*0602 were significantly greater in patients with ATL and asymptomatic carriers than in patients with HAM/TSP. In addition, haplotypes DRB1*1101-DQB1*0301 and DRB1*1501-DQB1*0602 were significantly increased among patients with ATL compared with patients with HAM/TSP. CONCLUSIONS: These data suggest that host genetic background is an important factor in determining whether HTLV-I carriers develop either ATL or HAM/TSP.

Alleles↗

PubMed1998

Clinical, pathologic, and immunologic features of human T-lymphotrophic virus type I-associated infective dermatitis in children.

OBJECTIVES: To define the clinical and laboratory features associated with infective dermatitis (ID) and confirm its association with human T-lymphotrophic virus type I (HTLV-I). DESIGN: A case series of patients with ID were compared with patients with atopic dermatitis (AD), which is an important disease in the differential diagnosis of ID. SETTING: Patients were recruited from dermatology and pediatric clinics at the University Hospital of the West Indies and the Bustamante Children's Hospital, Kingston, Jamaica. MAIN OUTCOME MEASURES: Clinical and laboratory features of patients with AD were compared with those of patients with ID. PATIENTS: Consecutive patients older than 1 1/2 years diagnosed as having ID (n=50) and AD (n=35) were enrolled based on clinical findings. RESULTS: The mean ages of patients with ID and AD were 6.9 and 7.8 years, respectively. Histologically, both diseases were predominantly chronic dermatitis with propensity for skin colonization with Staphylococcus aureus and beta-hemolytic streptococci; however, the distribution of sites of skin involvement differed. Infection with HTLV-I was the most distinguishing feature among patients with ID, with seropositive results in 100%; only 5 (14%) of the 35 patients with AD had results seropositive for HTLV-I. Infective dermatitis was further characterized by dermatopathic lymphadenitis in 16 (67%) of 24 patients with palpable nodes. Anemia, lymphocytosis, and low albumin and elevated serum globulin levels were more prevalent among patients with ID. Significant elevations of IgA, IgD, and IgG levels were observed among patients with ID compared with those with AD. However, both patients with AD and those with ID had levels of IgD and IgE elevated above the normal range. T-cell subsets among patients with ID revealed T-cell activation with a high percentage of HLA-DR antigen positivity, elevated CD4 (2.4 x 10(9)/L) and CD8 (1.4 x 10(9)/L) cell counts, with an increased CD4/CD8 ratio of 1:73. CONCLUSION: Infective dermatitis is a distinct clinical entity associated with HTLV-I, which plays a role in the pathogenesis and immune perturbations observed.

Adolescent↗

PubMed1998

The Trp64Arg mutation of the beta3-adrenergic receptor is associated with hyperglycemia and current body mass index in Jamaican women.

The Trp64Arg mutation of the beta3-adrenergic receptor (beta3-AR) has been linked to earlier onset of non-insulin-dependent diabetes mellitus (NIDDM), insulin resistance, abdominal obesity, and an increased capacity to gain weight in some European and Japanese populations. We studied the prevalence of the mutation and its association with NIDDM and obesity in our population, in which both rates are high, especially in women. The frequency of the homozygous mutation was 1.53%, and of the Arg allele, 10.5%. Rates were similar in men and women. Significantly higher body mass index (BMI), weight, hip circumference, and fasting and postchallenge 2-hour blood glucose concentrations were associated with the presence of the Arg allele in women but not in men. The association with weight and hip measurements and with hyperglycemia was present only in women aged less than 55 years. In multivariate analysis, the mutation was associated with the BMI and sex in a model that also included age. The variation in fasting and 2-hour blood glucose levels was predicted by beta3-AR, gender, age, and BMI. These results suggest that the presence of the mutation contributes to obesity and hyperglycemia in our female population.

Adult↗

PubMed1998

Microalbuminuria, renal function and waist:hip ratio in black hypertensive Jamaicans.

OBJECTIVE: To investigate the relationship between blood pressure (BP), renal haemodynamics, anthropometric measures of obesity and urinary albumin excretion in hypertension and in a control group. METHODS: Urinary albumin, BP and anthropometric measurements were carried out in patients attending the hypertension clinic of the University Hospital of the West Indies. A randomised stratified sample was then selected for renal haemodynamic assessment. A normoalbuminuric control group without hypertension or diabetes was also selected. Renal haemodynamics was assessed by measuring glomerular filtration rate using 51-chromium edetic acid (51Cr-EDTA) and renal blood flow using 125-iodohippurate (125-PAH). RESULTS: Urinary albumin excretion was positively and significantly correlated with systolic pressure (beta = 0.011, P < 0.003, R = 0.22), current body weight (beta = 0.014, P < 0.04, R = 0.15) and the presence of diabetes (beta = 0.9, P < 0.001, R = 0.3). In the sample selected for renal haemodynamics, patients with microalbuminuria had lower age-adjusted corrected renal blood flow (P < 0.006), effective renal plasma flow (P < 0.006) and higher filtration fraction (P < 0.006) when compared with patients without microalbuminuria. Glomerular filtration rate in patients with microalbuminuria was not different from those without. Urinary albumin excretion was positively and significantly correlated with systolic pressure (beta = 0.016, P < 0.003, R = 0.40) and inversely related to corrected renal blood flow (beta = -1.13, P < 0.0002, R = 0.46). Waist:hip ratio was inversely related to corrected renal blood flow (beta = -1.74, P < 0.02, adjusted R = 0.48). CONCLUSION: Systolic BP, diabetes and body weight were significant predictors of albuminuria in our patients. Microalbuminuria and body fat distribution as assessed by waist:hip ratio were important determinants of renal haemodynamics in this population.

Albuminuria↗

PubMed1998

Leptin and body composition of Nigerians, Jamaicans, and US blacks.

The role of leptin in humans remains controversial. Leptin concentrations are highly correlated with body fat stores. We tested whether or not this relation was consistent across the range of body composition encompassing the lean as well as the obese. Individuals participating in community-based comparative research in Nigeria (n = 363), Jamaica (n = 372), and the United States (Maywood, IL; n = 699) had their plasma leptin concentrations and body compositions (with bioelectrical impedance analysis) measured. All participants identified themselves as being black. Body mass index (in kg/m2) ranged from 14 to 62. Large differences in mean plasma leptin were noted across populations for both men and women in Nigeria, Jamaica, and the United States, respectively (men: 2.8, 3.9, and 6.8 microg/L; women: 10.3, 18.6, and 27.7 microg/L). An exponential function fit the relation between percentage body fat or total fat mass and leptin for men and women at each site. For women and men the exponential function with either percentage body fat or total fat mass was of the same shape, but increased by a constant in women, yielding higher leptin concentrations than in men at every level of body fat. On the basis of this broad distribution of body composition, the data suggest an exponential response of leptin to increases in body fat stores, consistent with the development of leptin resistance in individuals developing obesity. These findings likewise confirm that men and women exhibit different set points in terms of leptin production.

Adipose Tissue↗

PubMed1998

Chronic diseases: the new epidemic.

Mortality statistics show that there has been a significant change in the leading causes of death in Jamaica over the last 50 years, characterized by a decrease in the infectious diseases and those due to undernutrition and an increase in the non-communicable diseases. The various patterns of this epidemiological transition worldwide are outlined and the characteristics of this 'new' epidemic are discussed. Data are presented from the findings of the recent multi-country study of hypertension and diabetes, including Jamaica, which shows that as the body mass index (BMI) increases across the African diaspora, so does the prevalence of hypertension and diabetes. Among the Jamaican population studied, the prevalence of hypertension was 19.1% among males and 28.2% among females. Reported prevalence of previously diagnosed diabetes was 5.3% in men and 10.4% in females. The gender differences are in part explained by the differences in mean BMI which were 23.8 and 27.9, respectively, for males and females. 30.6% of males and 64.7% of females were either overweight or obese, with obesity prevalent in 7.2% of the males and 31.5% of the females studied. The increasing prevalence of obesity across the Caribbean is cause for concern as it significantly impacts on the demand for health and medical care. The identification of these reversible risk factors should be used to inform public policy to tackle what will be a growing concern.

Adult↗

PubMed1997

Relation between body mass index and body fat in black population samples from Nigeria, Jamaica, and the United States.

Body mass index (BMI) is the most commonly used measure of obesity. Recently, some investigators have advocated direct measurement of adiposity rather than use of the BMI. This study was undertaken to determine the ability of BMI to predict body fat levels in three populations of West African heritage living in different environments. A total of 1,054 black men and women were examined in Nigeria, Jamaica, and the United States during 1994 and 1995. A standardized protocol was used to measure height, weight, waist and hip circumferences, and blood pressure at all sites; percentage of body fat was estimated using bioelectrical impedance analysis. Percentage of body fat and BMI were highly correlated within site- and sex-specific groups, and the resulting r2 ranged from 0.61 to 0.85. The relation was quadratic in all groups except Nigerian men, in whom it was linear. The regression coefficients were similar across sites, yet the mean body fat levels differed significantly (p < 0.001) as estimated by the intercept, making intersite comparison difficult. Compared with BMI, percentage of body fat was not a better predictor of blood pressure or waist or hip circumference.

Adult↗

PubMed1997

The angiotensin converting enzyme and blood pressure in Jamaicans.

An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme gene influences the level of serum angiotensin converting enzyme activity and has been associated with risk of several cardiovascular conditions. The relationship to blood pressure remains uncertain, however. We conducted a population-based survey in Kingston, Jamaica, to examine the association between angiotensin converting enzyme genotype, angiotensin converting enzyme serum activity and blood pressure. Serum angiotensin converting enzyme activity was measured and genotyping performed for the I/D polymorphism in 500 community residents. The overall prevalence of the D allele was 59.3%. Angiotensin converting enzyme genotype was not significantly related to blood pressure (P = .16), although it did influence angiotensin-converting enzyme activity, leading to an increase of 35% among individuals with the DD as compared with II genotype. Angiotensin converting enzyme levels were significantly higher in hypertensives as compared with normotensives (P < .05). A modest correlation was observed between blood pressure and angiotensin converting enzyme activity among untreated individuals (r = 0.11; P = .04), although this did not persist in multivariate analysis. A relationship between body mass index and angiotensin converting enzyme activity was identified in both men and women that was independent of genotype. These data demonstrate findings among blacks which are consistent with other studies and suggest a relationship between angiotensin converting enzyme genotype, and serum activity which is influenced by both genetic and environmental factors. The potential role of ACE on blood pressure control in the population remains uncertain.

Adult↗

PubMed1997

ACE, angiotensinogen and obesity: a potential pathway leading to hypertension.

The renin-angiotensin system (RAS) plays a crucial role in the regulation of fluid volume, thereby influencing blood pressure (BP). Obesity is an important risk factor for hypertension, however the physiologic basis for this relationship has not been clarified. In a population survey we examined the potential relationship between the RAS and obesity. Based on community sampling, 449 individuals were recruited from metropolitan Kingston, Jamaica. Serum angiotensin-converting enzyme (ACE) and circulating angiotensinogen levels were measured and the associated genes were typed for previously described polymorphisms. Obese individuals (body mass index > 31) had significantly higher serum ACE and angiotensinogen levels, this relationship persisted for ACE in multivariate analyses controlling for BP, hypertension status, age, and gender. The insertion/deletion polymorphism of the ACE gene was associated with variation in the levels of ACE, but inconsistently with body mass index. Variants of the angiotensinogen gene leading to amino acid substitutions at positions 174 and 235 did not influence levels either of angiotensinogen or obesity. These data suggest that obesity may alter the levels of ACE and angiotensinogen, and provide a potential pathway through which obesity leads to elevation of BP.

Adult↗

PubMed1997

Leptin concentration in women is influenced by regional distribution of adipose tissue.

Leptin concentrations in humans are increased with obesity, and women have higher leptin concentrations than men. This sex difference reflects the greater fat mass of women. However, there is evidence that factors other than the size of the adipose tissue mass contribute to serum leptin concentrations. This study was undertaken to determine whether anthropometric factors influenced leptin concentrations in our population. Leptin concentrations were measured in 375 persons from a population study of hypertension and diabetes for whom body-composition data (bio-electrical impedance analysis and anthropometry) were available. Serum leptin concentrations were more than four times higher in women than in men (18.5 +/- 13.9 compared with 3.8 +/- 3.6 ng/L, P < 0.0001). In individuals with comparable body mass indexes, these differences persisted after adjustment for either percentage fat (P < 0.05) or fat mass (P < 0.0001) by multivariate-regression analysis. After fat mass was adjusted for, the serum leptin concentration in both men and women was independent of waist circumference but in women was associated with hip circumference. Hip circumference is a proxy measure of peripheral fat and these results suggest that the larger hips of women may contribute to the sex difference in serum leptin concentration.

Adipose Tissue↗