Age and gender exert differential effects on blood lipids in patients after LAGB and LRYGB

Abstract Background Although bariatric surgery is known to exert favorable effects on dyslipidemia, few studies have systematically considered how the demographic variables might modulate the outcomes. The aim of the present study was to examine the interactive effects of gender, age, and surgery type on dyslipidimia in bariatric surgery patients at a tertiary hospital in the United States. Methods In a retrospective review of 294 patients who had undergone laparoscopic Roux-en- Y gastric bypass (LRYGB) or laparoscopic adjustable gastric bypass (LAGB), we examined the changes in lipid profiles and antihyperlipidemic use for ≤4 years postoperatively. The data were analyzed using longitudinal mixed modeling methods, in which the effects on lipid concentrations and medication use were tested in models with gender, surgery type, age, postoperative duration, and all possible interactions entered as factors. Results Significant 2-way interactions of surgery type*time were found for total cholesterol and high-density lipoprotein cholesterol, gender*time for high-density lipoprotein cholesterol, and age*time for triglycerides. A 3-way interaction of surgery type*age*time was noted for low-density lipoprotein cholesterol. For older patients, low-density lipoprotein cholesterol was reduced by 20% from baseline in the LRYGB group but did not lessen significantly in the LAGB group. In the younger patients, however, decreases from the preoperative concentrations were not evident in either surgery group. An interaction of surgery type*time on antihyperlipdemic medication use, in which values changed significantly from baseline was found in both groups. However, the pattern in the LRYGB patients opposed that in the LAGB patients. Conclusion Our results have demonstrated that bariatric surgery imparts a pronounced improvement in the blood lipid profile of recipients; however, these effects might be moderated by other factors, such as age and gender, independently of the baseline weight status of the patients.