We undertook this study to assess the hypothesis that hypomagnesemia is associated with depressive symptoms in older people with diabetes.
A total of 55 type 2 diabetic patients, aged 65 years or older, with depressive symptoms were compared with a control group of diabetic subjects without depressive symptoms in an age- and gender-matched case/control study. A score >or=11 points in the Yesavage's scale was used for defining depressive symptoms, and hypomagnesemia was defined by serum magnesium levels <0.74 mmol/L. Well-known causes for depression as well as diseases and drugs that may cause depressive symptoms or hypomagnesemia were exclusion criteria.
Serum magnesium levels were significantly lower among depressive than control diabetic subjects (0.74 +/- 0.25 vs. 0.86 +/- 0.29 mmol/L, p = 0.02). Twenty four (43.6%) and 7 (12.7%) individuals in the case and control group exhibited low serum magnesium levels (p = 0.0006). The adjusted logistic regression analysis showed an independent association between hypomagnesemia and depressive symptoms (OR 1.79; CI(95%) 1.1-6.9, p = 0.03).
Our results suggest that hypomagnesemia is independently associated with depressive symptoms in older people with diabetes.