Abstract
Objective
To determine an association between magnesium (Mg) depletion and chondrocalcinosis, which has been reported but not investigated in a crossβsectional study.
Methods
Prevalence of chondrocalcinosis was investigated in 144 individuals: 72 patients receiving home parenteral nutrition (HPN) compared with 72 ageβ and sexβmatched controls. Presence of chondrocalcinosis was assessed by knee radiographs. Blood serum and globular Mg levels and 24βhour urinary Mg content were compared.
Results
Mean Β± SD age for both patients and controls was 51 Β± 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] 1.45β66.1). Mean Β± SD serum and globular Mg levels were significantly lower in patients than controls (serum: 0.75 Β± 0.09 mmoles/liter versus 0.81 Β± 0.08 mmoles/liter, P = 0.0006; globular Mg: 1.8 Β± 0.31 mmoles/liter versus 2.0 Β± 0.35 mmoles/liter, P = 0.0003). Twentyβfourβhour urinary Mg level was lower in patients than controls (mean Β± SD 3.85 Β± 1.50 mmoles versus 5.37 Β± 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 2.76β127.3, 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 0.603β20.26, P = 0.08) and in patients with a low 24βhour urinary Mg level (OR 3.9, 95% CI 0.77β16.34, P = 0.05).
Conclusion
Longβlasting Mg depletion is strongly associated with chondrocalcinosis.