Obesity, independent of insulin resistance, is a major determinant of blood pressure in normoglycemic Hong Kong Chinese

Obesity and insulin resistance are considered important links underlying the development of hypertension. In Caucasians, there have been many reports of an association between insulin resistance and hypertension. However, this relationship is not consistently found in other ethnic groups. In this study, we examined the involvement of insulin resistance (assessed as fasting insulin-glucose product, FIGP) and general and central obesity as potential links in the development of hypertension in 413 normoglycemic Hong Kong Chinese (56.9% hypertensive) subjects. Anthropometric parameters (waist circumference [WC], waist-to-hip ratio [WHR], body mass index [BMI]), surrogate measures of insulin resistance (fasting plasma glucose, insulin, FIGP), fasting lipids and systolic (SBP) and diastolic (DBP) blood pressure were measured. Both male and female hypertensives were more obese and dyslipidemic, and the females had higher indices of insulin resistance than the normotensive subjects of the same gender. Before adjustment for age, gender, and adiposity, FIGP correlated with SBP in the total (r = .19, P = .009) and low BMI (r = .23, P < .05) and low WHR (r = .25, P < .01) groups. However, after adjustment, there was no significant relationship between FIGP and blood pressure. In contrast, BMI and WC were strongly associated with blood pressure (r > or = .41, P < .001 for both DBP and SBP in the total population), although in the group with general obesity, the strength of the relationship was weaker (r > or = .13). These relationships persisted after adjustment for age, gender, and FIGP. Obesity, therefore, appears to have a predominant role compared with insulin resistance in determining blood pressure in these normoglycemic Chinese.