Zinc deficiency in patients with type 2 diabetes increases risk of cardiovascular diseases: Tehran Lipid and Glucose Study

BACKGROUND AND AIM: This study aimed to assess the prospective association between zinc (Zn) deficiency and the risk of cardiovascular diseases (CVD), CVD mortality and all-cause mortality in adults with type 2 diabetes (T2DM). METHOD: This prospective cohort study, embedded in the Tehran Lipid and Glucose Study (TLGS), including 632 adults with T2DM (mean age = 59.6 ± 12.4 years, 38% men) enrolled at 2009-2011 and followed until 2020. Serum zinc (SZn) concentrations were measured using flame atomic absorption spectrometry (FAAS), and Zn deficiency was defined as SZn < 85 µg/dL. Multivariable Cox proportional hazard models were used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of outcomes in the Zn-deficient compared to Zn-sufficient group. RESULTS: Mean baseline SZn concentration was 116 ± 44.5 µg/dL, and 22% were Zn-deficient. Over a median follow-up of 9.3 years, 34.7% of participants experienced incident CVD events, while 6.3% and 18.5% died from CVD and all causes, respectively. Zn deficiency was associated with a significantly increased risk of CVD events (HR = 1.86, 95%CI = 1.06-3.28, P = 0.031) in the fully adjusted model. Each 10 µg/dL increase in SZn was associated with a borderline-significant reduced risk of CVD (HR = 0.97, 95%CI = 0.93-1.00, P = 0.050). Zn status was not associated with CVD mortality or all-cause mortality. CONCLUSION: Zn deficiency is associated with a significantly increased risk of CVD events in patients with T2DM. Increased SZn concentration was associated with reduced risk of CVD events in patients with T2DM.