Relationship between serum gamma-glutamyl transferase and pulse pressure in apparently healthy middle-aged subjects

Higher values of pulse pressure (PP)--the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP)--are associated with an increased cardiovascular risk; SBP and DBP values are correlated with serum levels of gamma-glutamyl transferase (GGT), both in drinkers and non-drinkers subjects. Moreover, some studies showed that high levels of serum GGT might be related with an increased cardiovascular risk. However, few studies analyzed the relationship between GGT and PP. In 72 subjects (18 male; 54 women), middle-aged (mean age: 36.63 yrs; limits: 24-54 yrs), apparently healthy, we performed the measurements of: weight, height (from which we calculated the body mass index [BMI]), SBP, DBP, PP, standard biochemical workup, including GGT (UI/l).

PP values are correlated with SBP (r=0.74, p<0.001), but not with DBP (r=0.15, p=NS) values. GGT is significantly correlated with SBP (r=0.28, p=0.01), DBP (r=0.29, p=0.01), and BMI (r=0.41, p<0.001). Mean values of PP are significantly higher in those with a GGT>20 than those with GGT<20 (48.69 vs. 43.85 mmHg, p<0.05); similarly, mean values of SBP (131.66 vs. 116.81 mmHg, p=0.0004) and DBP (82.59 vs. 73.52 mmHg, p=0.0008) are higher in the group with GGT>20. We observed an ascending trend of the mean value of GGT in the different groups of PP; therefore, mean value of GGT was 19.21, 22.65, 23.18 in the PP<40, PP=40-60, respectively PP>60 groups. However, the correlation between PP and GGT was not significant, both in univariate analysis (r=0.14, p=NS) and after adjusting for SBP, DBP, BMI (r=0.12, p=NS). When we analyzed subgroups, the relationship between GGT and PP was more evident in women and in subjects with increased values of BMI.

GGT values are significantly correlated with SBP and DBP, but not with PP, in middle-aged, apparently healthy subjects; even though the highest values of GGT are associated with an increased PP value, further studies would be necessary in order to explain this link.