Gender differences in the association between serum γ-glutamyltransferase and blood pressure change: A prospective community-based cohort study

We evaluated the gender differences in the relation of baseline serum γ-glutamyltransferase (GGT) levels to blood pressure (BP) change during 4 yr. 4,025 normotensive subjects (1,945 men and 2,080 women) who aged 40-69 yr at baseline participated in the Ansung-Ansan cohort of the Korean Genome Epidemiology Study were included. The associations of GGT with baseline BP or 4-yr change of BP were evaluated. GGT levels were associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline after adjusting for age, body mass index (BMI), HDL-cholesterol, triglyceride, C-reactive protein (CRP), current smoking status and alcohol intake (SBP, β=1.28, P < 0.001; DBP, β=1.41, P < 0.001). GGT levels were also associated with 4-yr change in BP after adjusting for age, BMI, HDL-cholesterol, triglyceride, CRP, current smoking status, alcohol intake and SBP (SBP, β=1.08, P=0.001; DBP, β=0.64, P=0.003). This association was statistically significant in men (SBP, β=1.82, P < 0.001; DBP, β=1.05, P=0.001), but not in women (SBP, β=0.38, P=0.466; DBP, β=-0.37, P=0.304). Remarkably, this association between GGT and BP was significant in men at 40-49 yr of age. In summary, we found positive associations between GGT levels at baseline and the change of BP. The relation of GGT level and the change of BP was only significant in men, not in women, which warrants further studies to elucidate the biologic mechanisms.