Sex-specific relations between fasting insulin, insulin resistance and incident hypertension: 8.9 years follow-up in a Middle-Eastern population

The purpose of this study was to investigate whether fasting serum insulin levels, homeostasis model assessment of insulin resistance (homa-ir) and insulin-to-glucose ratio (igr) were associated with incident hypertension. in a prospective study, 4093 iranian participants (1725 men and 2368 women) without hypertension and known diabetes at baseline (1999–2001) were followed for a median of 8.9 years. regular follow-up examinations were performed at 3-year intervals. multivariate cox proportional hazard models were used to calculate hazard ratios (hrs) and 95% confidence intervals (cis) of incident hypertension adjusting for sex, and in sex-stratified models. during the study, 896 incident cases of hypertension (432 men and 464 women) were identified (total incident rate: 27.5 per 1000 person-years). in the multivariable models, serum insulin level, homa-ir and igr were positively associated with hypertension incidence, adjusting for sex. in the sex-stratified analyses, after adjusting for potential confounders, women in the highest quartile of insulin, homa-ir and ig had a significantly higher incidence of hypertension, compared with those in the lowest quartile (hr: 1.7 (95% ci 1.26–2.30); hr: 1.80 (95% ci 1.31–2.40) and hr: 1.67 (95% ci 1.26–2.22), respectively); among men, these relations were also significant, until including waist circumference and body mass index in the models (hr: 1.17 (95% ci 0.85–1.62), hr: 1.25 (95% ci 0.91–1.73) and hr: 1.06 (95% ci 0.77–1.45), respectively). higher fasting serum insulin levels, homa-ir and igr were associated with incident hypertension among women, whereas these associations were not significant after adjusting for obesity measures in men.