Blood pressure in Jamaican children: relationship to body size and composition

Blood pressure levels in adults and children are related to body size and composition, but some of these relationships are unclear and they have been incompletely described in the Jamaican population. In a cross-sectional survey of 2,332 school children (6-16 years old; 1,046 boys, 1,286 girls), we measured systolic and diastolic blood pressure and pulse rate, and explored their relationship to weight, height, and waist, hip and mid-upper arm circumferences. The effect of these and other derived measures of body composition on blood pressure was explored in univariate and multivariate analysis. Blood pressure increased with age in both boys and girls, although the increase was greater for systolic than for diastolic blood pressure. The increase of systolic blood pressure among boys continued after age 11 years, but that for girls levelled off. Height and weight were the major predictors of blood pressure, but were highly correlated with each other and with all measures of body composition. Age, height and height-sex interaction explained 11.4 percent of systolic blood pressure variation, and the largest incremental contribution to this model was provided by the addition of body mass index or hip circumference, each explaining an additional 2.6 percent of the variance. Lean body mass made a larger contribution to blood pressure than percent fatness. Blood pressure in Jamaican children rises with age and this rise may be steeper in boys than girls. Blood pressure variation is significantly related to several measures of body composition including measures of fatness and fat free masses.(AU)

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 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 assess by measured glomerular filtration rate using 51-chromium edetic acid (51 Cr-EDTA) and renal blood flow using 125-iodohippurate (125-PAH). RESULTS: Urinary albumium excretion was postively and significantly correlated with systolic pressure (B = 0.011, P < 0.003, R = 0.22), current body weight (B = 0.014, P < 0.04, R = 0.15) and the pressure of diabetes (B = 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) when compared with patients without microalbuminuria was not different from those without. Urinary albumin excretion was postively and significantly correlated with systolic pressure (B = 0.016, P < 0.003, R = 0.40) and inversely related to corrected renal flow (B = -1.13, P < 0.0002, R = 0.46) Waist: hip ratio was inversely related to corrected renal blood flow (B = -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.(AU)