Gender differences in lipid alterations following combined pancreas-kidney transplantation

Abstract

We have previously demonstrated that the lipid profile improves following successful combined pancreas-kidney transplantation (PKT). In this study, we examined whether changes in the lipid profile were different in men than in women following PKT. Fasting total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and the TC to HDL ratio (TC/HDL) were evaluated in 47 patients (27 men and 20 women) with normal graft function following PKT. Lipids were evaluated at regular intervals 3.5 months to 2.2 years post-PKT (a total of 317 observations). After PKT, TC/HDL decreased ( P < .05), TC was unchanged, and HDL increased ( P < .05) in both men and women. Although TG decreased in both men and women, it reached statistical significance in men only ( P < .05). There were no significant differences in any lipid parameters between men and women before PKT, but after PKT, TC, TG, and HDL were higher in women (240 ± 11, 183 ± 17, and 64 ± 19 mg/dL, respectively) than in men (207 ± 6, 143 ± 11, and 53 ± 2 mg/dL, P < .05 for each). When post-PKT values were analyzed for trends over time, both TC and TG decreased ( P < .05 for both) without any significant difference in trends between men and women. When six individuals who had received lovastatin at any time during their postoperative course were removed from analysis, the gender differences in TG post-PKT and the decrease in TG over time were no longer statistically significant ( P > .05). There were no differences in age, time elapsed since PKT, body mass index (BMI), frequency of smokers, frequency of those on dialysis before PKT, duration of diabetes, or glycohemoglobin either pre- or post-PKT between men and women to explain the gender differences in lipids. Serum creatinine was slightly greater in men than in women, as would be expected with greater muscle mass (175 ± 3 v 140 ± 3 μmol/L, P < .01). No women but 10 men were treated with β-blockers both before and after PKT, yet there was no difference in lipids between those men taking and not taking β-blockers. The final and most likely variable was an improvement in gonadal function in some women. Seventeen of the 20 women were premenopausal at the time of study. Ten of these 17 women had regular menstrual cycles before PKT, whereas 16 had regular cycles after PKT. Measurement of gonadal steroid levels will be needed to confirm the hypothesis that improved sex steroid secretion results in a greater increase in HDL in women than in men following PKT. Thus, assessment of gonadal function both before and after PKT may be important for the interpretation and treatment of abnormal lipid profiles in this clinical setting.