Evaluation of Glycated Hemoglobin and Lipid Profile in Type 2 Diabetes Mellitus: A Systematic Review
Abstract
Background: Type 2 diabetes mellitus (T2DM) is frequently accompanied by dyslipidemia, both of which contribute independently and synergistically to cardiovascular risk. Glycated hemoglobin (HbA1c) reflects long-term glycemic control and has been proposed as an indirect marker of lipid abnormalities in T2DM. This systematic review evaluated the relationship between HbA1c and lipid profile parameters in patients with T2DM. Material and Methods: A systematic search of electronic databases was conducted for studies published between January 2021 and September 2026 reporting an association between HbA1c and lipid parameters (total cholesterol, triglycerides, LDL-C, HDL-C) in adults with T2DM. Studies were screened against predefined eligibility criteria, and data were extracted on study design, population, and outcomes. Findings were synthesized narratively due to methodological heterogeneity. Results: Twenty-one studies from diverse regions, including India, the Middle East, South Asia, and Africa, were included. Ten studies directly assessed HbA1c–lipid correlations, most reporting significant positive associations between HbA1c and triglycerides and/or total cholesterol, with more variable findings for LDL-C and HDL-C. Four studies focused on glycemic control prevalence and determinants, reporting poor glycemic control in over half of participants in several settings. Three studies examined lipid-lowering therapy and target achievement, showing suboptimal overall lipid control despite treatment. Four studies reported HbA1c or lipid data as secondary outcomes within broader investigations. Conclusion: HbA1c correlates consistently with triglycerides and total cholesterol across diverse populations, supporting its use as an indirect marker of dyslipidemia in T2DM, though predominantly cross-sectional designs limit causal inference. Key words: Type 2 diabetes mellitus; Glycated hemoglobin; Lipid profile; Dyslipidemia; Glycemic control; Cardiovascular risk.