ARE BODY-MASS OR INSULIN-RESISTANCE INDEPENDENTLY ASSOCIATED WITH CARDIOVASCULAR RISK-FACTORS IN NONDIABETIC ELDERLY NIGERIANS

The aim was to establish whether risk factors for cardiovascular disea se (CVD) are positively and independently associated with fasting insu lin and/or body mass and waist-hip ratio in healthy elderly Nigerian s ubjects. Easting plasma glucose, insulin, total cholesterol, triglycer ides, blood pressure, and basal insulin resistance (HOMA method) were measured in 500 healthy elderly (greater than or equal to 55 years) Ni gerian volunteers (295 men, 205 women). Associations between blood pre ssure, triglycerides or cholesterol and fasting insulin, HOMA, body ma ss index (BMI) or waist-hip ratio were examined using linear regressio n. Age was controlled for in all analyses. In men, diastolic and systo lic blood pressure were strongly associated with BMI, while there was no evidence of an independent relationship with fasting insulin or HOM A. Triglycerides were strongly associated with waist-hip ratio, with a weaker independent association with HOMA but not fasting insulin; fas ting insulin and HOMA showed strong independent associations with tota l cholesterol. In women diastolic and systolic blood pressure were als o strongly associated with BMI, but there was an independent relations hip with fasting insulin for diastolic blood pressure and a less signi ficant (p = 0.057) one for systolic blood pressure. Triglycerides were significantly associated with BMI but none of the other variables; th ere were no significant associations with cholesterol. There was no ev idence of interaction between fasting insulin or HOMA and BMI or waist -hip ratio. The results suggest the hypotheses that in this population BMI or waist-hip ratio are stronger determinants of blood pressure an d triglyceride levels than fasting insulin or HOMA, and that where ins ulin does play a role its effects are separate and additive.