Fasting Insulin Level Is Positively Associated With Incidence of Hypertension Among American Young Adults: A 20-year follow-up study

Diabetes Care, 05/01/2012

Xun P et al. – Fasting serum insulin levels or hyperinsulinemia in young adulthood was positively associated with incidence of hypertension (HTN) later in life for both men and women, African Americans and Caucasians, and those with normal weight and overweight. The findings suggested that fasting insulin ascertainment may help clinicians identify those at high risk of HTN.


  • A prospective cohort of 3,413 Americans, aged 18–30 years, without HTN in 1985 (baseline) were enrolled.
  • Six follow-ups were conducted in 1987, 1990, 1992, 1995, 2000, and 2005.
  • Fasting insulin and glucose levels were assessed by a radioimmunoassay and hexokinase method, respectively.
  • Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% CIs of incident HTN (defined as the initiation of antihypertensive medication, systolic blood pressure ≥140 mmHg, or diastolic blood pressure ≥90 mmHg).


  • During the 20-year follow-up, 796 incident cases were identified.
  • After adjustment for potential confounders, participants in the highest quartile of insulin levels had a significantly higher incidence of HTN (HR 1.85 [95% CI 1.42–2.40]; Ptrend < 0.001) compared with those in the lowest quartile.
  • The positive association persisted in each sex/ethnicity/weight status subgroup.
  • A similar dose-response relation was observed when insulin-to-glucose ratio or homeostatic model assessment of insulin resistance was used as exposure.

Author Commentary

We believe our study will make important additional contribution to the literature because of the following reasons: 1) A randomized placebo-controlled trial on insulin and hypertension may not be feasible, which makes the results from a well-designed prospective cohort study with relatively large sample size and long-term follow-up highly valuable; 2) blood pressure of our participants is measured by trained personnel using standardized procedures rather than self-reported, which may substantially reduce the possible measurement error in blood pressure; and 3) the participants at baseline were at their ages of 18-30, which enable us to investigate the evolution of CVD risk by following the course of blood pressure and the appearance of incident hypertension in young adulthood.

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