[Hypercalcemia after hyperkalemia]. / Hypercalciëmie na een hyperkaliëmie.

BACKGROUND: Hyperkalemia is a common yet dangerous phenomenon in patients with chronic kidney disease (CKD). Patients suffering from CKD are therefore often treated with potassium-binding supplements such as calcium polystyrene sulfonate (CPS). Hypercalcemia is a known side effect of CPS. However, the increase in serum calcium is usually small. CASE DESCRIPTION: A 68 year old male patient suffering from CKD was treated with a daily administration of 80mg CPS. He presented with complaints of a dry mouth, thirst and malaise. Blood tests showed an elevated serum calcium of 3,25 mmol/L (2,15- 2,55 mmol/L). Additional diagnostics revealed no abnormalities. The hypercalcemia was attributed to the use of CPS only after the exclusion of a wide differential diagnosis. CONCLUSION: Although CPS induced hypercalcemia is usually mild, a more severe course is possible. Knowledge about the composition of medication is paramount to prevent such side effects.

Relationship between de novo lipogenesis and serum sex hormone binding globulin in humans.

OBJECTIVE: Obesity and liver fat are associated with decreased levels of serum sex hormone binding globulin (SHBG). Laboratory studies suggest that hepatic de novo lipogenesis (DNL) is involved in the downregulation of SHBG synthesis. The aim of the present study was to address the role of DNL on serum SHBG in humans. DESIGN: A cross-sectional study examining the association between DNL, measured by stable isotopes, and serum SHBG, stratified by sex. PARTICIPANTS: Healthy men (n = 34) and women (n = 21) were combined from two cross-sectional studies. Forty-two per cent of participants had hepatic steatosis, and the majority were overweight (62%) or obese (27%). RESULTS: DNL was inversely associated with SHBG in women (ß: -0.015, 95% CI: -0.030; 0.000), but not in men (ß: 0.007, 95% CI: -0.005; 0.019) (p for interaction = .068). Adjustment for study population, age and body mass index did not materially change these results, although statistical significance was lost after adjustment for serum insulin. CONCLUSIONS: An inverse association between DNL and SHBG may explain the decreased SHBG levels that are observed in obesity, at least in women.