Association and diagnostic efficacy of waist-to-height ratio with glycemic control in young and middle-aged adults with early-onset type 2 diabetes mellitus

To investigate the cross-sectional association between waist-to-height ratio (WHtR) and glycemic control among Chinese young and middle-aged adults with early-onset type 2 diabetes mellitus (T2DM), and to evaluate the clinical value of WHtR as a screening indicator for early-onset T2DM. This single-center retrospective cross-sectional study enrolled 302 patients with early-onset T2DM (diagnosed at age ≥ 18 and < 40 years) who attended the Endocrinology Department of Fuzhou Second General Hospital between March 2023 and March 2024. Demographic, lifestyle, anthropometric, and glucolipid metabolic data were collected. WHtR and body mass index (BMI) were calculated. Patients were divided into three groups by tertiles of WHtR. Spearman correlation was used to explore the relationship between WHtR and glycemic parameters. Multivariate logistic regression was performed to verify the independent association between WHtR and poor glycemic control (glycated hemoglobin [HbA1c] ≥ 7.0%). Receiver operating characteristic (ROC), calibration, and decision curve analyses (DCA) were conducted to comprehensively assess the diagnostic performance and clinical utility of WHtR. Among 302 included patients, 185 (61.3%) were male, with a mean age of 31.77 ± 8.63 years, mean HbA1c of 7.08 ± 1.23%, and mean WHtR of 0.55 ± 0.07. The poor glycemic control group (HbA1c ≥ 7.0%, n = 155) had significantly higher WHtR, BMI, fasting plasma glucose (FPG), and 2-hour postprandial plasma glucose (2 h-PPG) than the good control group ( n = 147, all P < 0.001). Glycolipid metabolic parameters and diabetes distress scale (DDS) scores increased stepwise with rising WHtR tertiles (all P for trend < 0.01). WHtR was positively correlated with HbA1c ( r = 0.464, P < 0.001), and the correlation strength was significantly higher than that of BMI ( r = 0.320, P < 0.001). After adjustment for multiple confounders (including antidiabetic treatment regimens and diabetes duration), WHtR remained an independent factor associated with poor glycemic control (odds ratio [OR] = 5.80, 95% confidence interval [CI] 3.12–10.79, P < 0.001). The area under the curve (AUC) of WHtR for identifying poor glycemic control was 0.757, which was significantly higher than that of BMI (AUC = 0.675, P = 0.021), with acceptable discriminatory accuracy, calibration, and clinical net benefit. WHtR is closely associated with glycemic control in Chinese young and middle-aged adults with early-onset T2DM and shows acceptable screening and diagnostic performance for this population. WHtR is simple, non-invasive, and suitable for widespread use in primary clinical settings. Not applicable.