Hypomagnesemia associated with chondrocalcinosis: A cross‐sectional study

Objective

To determine an association between magnesium (Mg) depletion and chondrocalcinosis, which has been reported but not investigated in a cross‐sectional study.

Methods

Prevalence of chondrocalcinosis was investigated in 144 individuals: 72 patients receiving home parenteral nutrition (HPN) compared with 72 age‐ and sex‐matched controls. Presence of chondrocalcinosis was assessed by knee radiographs. Blood serum and globular Mg levels and 24‐hour urinary Mg content were compared.

Results

Mean ± SD age for both patients and controls was 51 ± 17 years, and 51% in both groups were women. Mean duration of HPN was 6.4 years. Prevalence of chondrocalcinosis was markedly higher in patients receiving HPN than controls (16.6% versus 2.7%; P = 0.006, odds ratio OR] 7.0, 95% confidence interval 95% CI] 1.45–66.1). Mean ± SD serum and globular Mg levels were significantly lower in patients than controls (serum: 0.75 ± 0.09 mmoles/liter versus 0.81 ± 0.08 mmoles/liter, P = 0.0006; globular Mg: 1.8 ± 0.31 mmoles/liter versus 2.0 ± 0.35 mmoles/liter, P = 0.0003). Twenty‐four‐hour urinary Mg level was lower in patients than controls (mean ± SD 3.85 ± 1.50 mmoles versus 5.37 ± 3.71 mmoles; P = 0.001). Prevalence of chondrocalcinosis was significantly higher in patients with a low serum Mg level (OR 13.5, 95% CI 2.76–127.3, P < 0.0001), with a similarly high but not significant occurrence of chondrocalcinosis in patients with a low globular Mg level (OR 4.09, 95% CI 0.603–20.26, P = 0.08) and in patients with a low 24‐hour urinary Mg level (OR 3.9, 95% CI 0.77–16.34, P = 0.05).

Conclusion

Long‐lasting Mg depletion is strongly associated with chondrocalcinosis.