Association of dietary and serum magnesium with glucose metabolism markers: The Furukawa Nutrition and Health Study. (April 2018) - Akter, Shamima
Summary: Background & aims: Magnesium may play an important role in cardio-metabolic abnormalities, including type 2 diabetes, but epidemiological evidence linking magnesium status to glucose metabolism is limited among Asians. We cross-sectionally examined the association of dietary and serum magnesium with markers of glucose metabolism among Japanese subjects. Methods: Subjects were 1796 workers, aged 18–78 years, who participated in a health survey. Dietary magnesium intake was assessed with a validated brief diet history questionnaire. Serum magnesium concentrations were measured using an enzymatic method. Multivariable linear regression models were used to estimate means of fasting insulin, fasting plasma glucose, homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β), and glycated hemoglobin (HbA1c), with adjustments made for potential confounding variables. Results: Dietary magnesium was inversely associated with HOMA-IR ( P trend = 0.01). Multivariable-adjusted means (95% confidence intervals) of HOMA-IR for the lowest to highest quartiles of dietary magnesium were 0.94 (0.89–0.99), 0.92 (0.88–0.97), 0.88 (0.83–0.92), and 0.86 (0.81–0.90). Serum magnesium concentrations were also inversely associated with HOMA-IR ( P trend = 0.04) and HbA1c ( P trend <0.01). Multivariable-adjusted means (95% confidence intervals) for the lowest to highest quartiles of serum magnesium were 0.94 (0.90–0.98), 0.87 (0.83–0.91), 0.90 (0.85–0.95), and 0.86 (0.81–0.92) for HOMA-IR and 5.41 (5.36–5.45), 5.33 (5.28–5.37), 5.30 (5.25–5.36), and 5.28 (5.22–5.35) for HbA1c. Excluding subjects with diabetes did not materially change the association between dietary magnesium and HOMA-IR ( P trend <0.01), while it attenuated the association of serum magnesium with HOMA-IR ( P trend = 0.27) and HbA1c ( P trend = 0.15). Conclusions: The present findings suggest that lower dietary magnesium, but not serum magnesium, is associated with IR in apparently healthy adults. Highlights: This study investigated the association of magnesium status with glucose metabolism markers. Magnesium intake was inversely associated with fasting insulin, HOMA-IR, and HOMA-β. Serum magnesium was not associated with any glucose metabolism markers.