Аннотация
Abstract Introduction The development of ethnic-specific reference values for β-cell secretion and insulin sensitivity requires simple and routinely available markers. The triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDL-C) is considered a surrogate marker of peripheral insulin resistance; however, its diagnostic thresholds for the Kazakh population have not yet been defined. Materials and methods A retrospective–prospective study was conducted in 100 apparently healthy Kazakh adults aged 18–70 years (42 ± 12 years; 56 women). Current fasting TG, HDL-C, glucose, and insulin levels were obtained in 2025, while archival lipid profiles from 2019–2024 were retrieved from the national electronic health system “Damumed”. The TG/HDL-C index was calculated; its diagnostic accuracy for insulin resistance (IR) was evaluated using ROC-curve analysis, and the optimal cutoff was determined by the Youden index. Results The median TG/HDL-C increased from 0.59 (0.42–1.09) in 2019–2024 to 0.71 (0.47–1.25) in 2025 (p < 0.001). The proportion of individuals with TG/HDL-C ≥ 3.0 rose from 2% to 4% of the sample. The correlation between TG/HDL-C and HOMA-IR was ρ = 0.46 (p < 0.001). ROC analysis demonstrated an AUC of 0.72 ± 0.06; the optimal cutoff of 1.1 provided 64% sensitivity and 79% specificity. A threshold ≥ 3.0 maintained 97% specificity with 9% sensitivity. Discussion The findings indicate a progressive increase in the atherogenicity of the lipid profile among apparently healthy Kazakh adults and confirm the utility of the TG/HDL-C index as a tool for early screening of insulin resistance. A cutoff of 1.0–1.2 is recommended as a practical criterion for use in primary health care, whereas a threshold ≥ 3.0 may serve as a highly specific marker warranting comprehensive metabolic evaluation. Automated calculation of the index for each lipid profile could facilitate the establishment of regional reference values for β-cell function and enable timely identification of individuals at elevated metabolic risk.