Comparison of Fasting, Two-Hour and Six-Hour Postprandial Lipid Profiles in Patients with Controlled Type 2 Diabetes Mellitus

Abstract

Background: Postprandial lipid changes may influence the interpretation of lipid profiles in patients with type 2 diabetes mellitus. Understanding variation at defined intervals after a meal can help clarify the relationship between fasting and postprandial measurements. Objective: To compare fasting, two-hour and six-hour postprandial lipid profiles in patients with controlled type 2 diabetes mellitus. Methods: This hospital-based prospective comparative observational study included 50 patients aged 35-65 years with controlled type 2 diabetes mellitus. Blood samples were collected after an overnight fast and at two and six hours after a meal. Total cholesterol, triglycerides and HDL-C were measured, while LDL-C and VLDL-C were calculated. Results were summarised as mean (SD), and differences across sampling times were assessed using repeated-measures ANOVA. A p value below 0.05 was considered statistically significant. Results: Mean triglycerides increased from 144.72 (73.41) mg/dL during fasting to 167.12 (85.76) mg/dL at two hours and 175.12 (79.46) mg/dL at six hours (overall p = 0.0001). HDL-C decreased from 56.00 (10.78) to 52.42 (9.63) and 51.10 (9.27) mg/dL, respectively (p = 0.0002). Reported VLDL-C increased from 28.94 (14.68) to 33.41 (17.16) and 34.95 (15.96) mg/dL (p = 0.0003). Overall differences in total cholesterol (p = 0.063) and reported LDL-C (p = 0.081) were not statistically significant. At six hours, the triglyceride group mean was 21.01% above fasting, while HDL-C was 8.75% lower. Pairwise significance could not be established from the available summary data, and calculated lipid values required verification. Conclusion: Postprandial changes were evident in triglycerides, HDL-C and reported VLDL-C, whereas total cholesterol and reported LDL-C showed smaller changes. Six-hour measurements did not uniformly approximate fasting concentrations. These findings support considering sampling time during interpretation but do not establish interchangeability between fasting and six-hour postprandial lipid profiles.