HIGH FASTING BLOOD GLUCOSE LEVEL INCREASE RISK OF HYPERTENSION INCIDENCE INDEPENDENT OF INSULIN RESISTANCE IN JAPANESE: THE SAKU STUDY

Abstract

Objective: Although high fasting blood glucose (FBG) levels is reported to be a risk factor for incidence of hypertension, the predominant confounding effect of insulin resistance may make the current evidence difficult to apply for individuals without insulin resistance. This study aimed to investigate whether high FBG levels increase the risk of incidence of hypertension, regardless of insulin resistance. Design and method: This 5-year cohort study included 2210 Japanese aged 30–64 years without hypertension. Participants were stratified by baseline homeostasis model assessment of insulin resistance (HOMA-IR) less than 1.6, 1.7–2.4 and 2.5 or higher. In each HOMA-IR stratum, hazard ratios (HRs) and 95% confidence intervals (CIs) of FBG 7.0 mmol/l or higher for the incidence of hypertension compared with FBG less than 7.0mmol/l were estimated using multivariable-adjusted Cox proportional hazard models. Hypertension was defined as blood pressure 140/90 mmHg or higher or receiving antihypertensive treatment. Results: Of 2210 participants, 334 participants showed increased BP levels to 140/90 mmHg or higher, and 212 participants started taking antihypertensive treatment during the median 4.9-year follow-up period (interquartile range: 3.5–5.0 years). After adjustment for age, sex, overweight, dyslipidaemia, smoking status, alcohol consumption, physical activity, family history of hypertension, and systolic BP at baseline, the HRs (95% CIs) of FBG 7.0 mmol/l or higher compared with FBG less than 7.0mmol/l were 1.94 (1.05–3.59), 2.94 (1.36–6.36) and 2.22 (1.03–4.78) in those with HOMA-IR less than 1.6, 1.7–2.4 and 2.5 or higher, respectively. Conclusions: FBG 7.0 mmol/l or higher increased future incidence of hypertension compared with FBG less than 7.0 mmol/l in middle-aged Japanese, regardless of insulin resistance defined by HOMA-IR.