Omer Toprak, Yasin Sarı, Akif Koç, Erhan Sarı, Ali Kırık

Erectile dysfunction (ED) is common in older men with chronic kidney disease. Magnesium is essential for metabolism of nitric oxide which helps in penile erection. There is little information available about the influence of serum magnesium on ED. The aim of the study was to assess the influence of hypomagnesemia on ED in elderly chronic kidney disease patients. A total of 372 patients aged 65-85 years, with an estimated glomerular filtration rate of 60-15 mL/min/1.73 m(2), were divided into two groups according to serum magnesium levels: hypomagnesemia, n=180; and normomagnesemia, n=192. ED was assessed through the International Index of Erectile Function-5. Hypomagnesemia is defined as serum magnesium <1.8 mg/dL. The prevalence of ED was higher among hypomagnesemic subjects compared to that among normomagnesemics (93.3% vs 70.8%, P<0.001). Severe ED (62.8% vs 43.8%, P=0.037), mild-to-moderate ED (12.2% vs 5.2%, P=0.016), abdominal obesity (37.2% vs 22.9%, P=0.003), metabolic syndrome (38.4% vs 19.2%, P=0.026), proteinuria (0.83±0.68 vs 0.69±0.48 mg/dL, P=0.023), and C-reactive protein (6.1±4.9 vs 4.1±3.6 mg/L, P<0.001) were high; high-density lipoprotein cholesterol (48.8±14.0 vs 52.6±13.5 mg/dL, P=0.009), and albumin (4.02±0.53 vs 4.18±0.38 g/dL, P=0.001) were low in the hypomagnesemia group. Serum magnesium ≤1.85 mg/dL was the best cutoff point for prediction of ED. Hypomagnesemia (relative risk [RR] 2.27), age ≥70 (RR 1.74), proteinuria (RR 1.80), smoking (RR 21.12), C-reactive protein (RR 1.34), abdominal obesity (RR 3.92), and hypertension (RR 2.14) were predictors of ED. Our data support that ED is related to hypomagnesemia in elderly patients with moderately to severely reduced kidney function.