High glucose variability is associated with 2.10 increased risk of all-cause mortality in COVID-19High blood sugar swings linked to higher COVID-19 death risk

BackgroundGlucose variability (GV) reflects fluctuations in blood glucose and may better capture metabolic instability than static glycemic measures in patients with Coronavirus disease 2019 (COVID-19). However, its association with mortality remains uncertain due to heterogeneous study designs and inconsistent findings. This meta-analysis was performed to evaluate the association between GV and short-term all-cause mortality in adult patients hospitalized with COVID-19.MethodsPubMed, Embase, and Web of Science were systematically searched for longitudinal observational studies reporting the association between GV and mortality in patients hospitalized with COVID-19. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using a random-effects model accounting for the possible influence of heterogeneity.ResultsTen cohort studies comprising 11 datasets and 77,395 patients were included, with 8,189 deaths. High GV was associated with a significantly increased risk of all-cause mortality (RR = 2.10, 95% CI: 1.69–2.59; I² = 45%). The association was stronger in studies with a mean age ≥ 62 years (RR = 2.79) compared with < 62 years (RR = 1.78; p for subgroup difference = 0.03). Results were consistent across GV metrics, analytic models, adjustment for diabetes status, and study quality (all p > 0.05). Meta-regression analysis showed that mean age demonstrated a borderline association with the effect estimate (coefficient = 0.020, p = 0.07), explaining a moderate proportion of heterogeneity (adjusted R² = 49.2%).ConclusionsHigher GV is associated with increased short-term mortality in hospitalized patients with COVID-19, supporting its role as a potential prognostic marker.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD420261358246.