Association between growth hormone and hypertension in a general population

Insulin-like growth factors are polypeptides, with arrays similar to insulin, and insulin-like growth factor 1 (IGF-1) is secreted via stimulation by growth hormone (GH) in the liver. The lack of both GH and IGF-1 leads to physiological age-related changes in the cardiovascular system; however, the role of IGF-1 and GH in hypertension has not been fully elucidated. Thus, we examined the association between plasma IGF-1 and GH levels and hypertension. Among 1368 health check-up examination participants in the town of Tanushimaru, 1094 subjects were analyzed after excluding subjects with diabetes mellitus or impaired liver function. Multiple linear and logistic regression analyses were performed for factors related to systolic and diastolic blood pressures (BPs). Characteristics of participants stratified by IGF-1 and GH quartiles were compared using analysis of covariance. We calculated odds ratios associated with each standard deviation increase in IGF-1 and GH levels for hypertension, which was defined as BP ≥ 140/90 mmHg and/or the use of antihypertensive medication. Multivariable analysis showed that FPG, insulin, HOMA-IR, eGFR, total cholesterol, triglycerides, and the use of medication for hypertension were associated with the Z-score of IGF-1 measurement quartiles. Next, we found that BMI, systolic and diastolic BPs, insulin, HOMA-IR, total cholesterol, HDL-cholesterol, triglycerides, smoking, and alcohol intake were associated with GH quartiles, indicating that hypertension was inversely associated with GH but not IGF-1. A significant and inverse relationship between serum GH and hypertension was found after adjustment for confounders. In conclusion, decreased GH but not IGF-1, was associated with hypertension in a general population.