Habitual carbohydrate intake is not correlated with circulating ß-hydroxybutyrate levels in pregnant women with overweight and obesity at 28 weeks' gestation.

AIMS/HYPOTHESIS: Pregnant women are advised to consume a minimum of 175 g per day of carbohydrate to meet maternal and fetal brain glucose requirements. This recommendation comes from a theoretical calculation of carbohydrate requirements in pregnancy, rather than from clinical data. This study aimed to determine whether fasting maternal ketone levels are associated with habitual carbohydrate intake in a subset of participants of the Study of PRobiotics IN Gestational diabetes (SPRING) randomised controlled trial. METHODS: Food frequency questionnaires on dietary intake during pregnancy were completed by pregnant women with overweight or obesity at 28 weeks' gestation (considering their intake from the beginning of pregnancy). Dietary intake from early pregnancy through to 28 weeks was analysed for macronutrient intake. At the same time, overnight fasting serum samples were obtained and analysed for metabolic parameters including serum ß-hydroxybutyrate, OGTTs, insulin and C-peptide. RESULTS: Fasting serum ß-hydroxybutyrate levels amongst 108 women (mean BMI 34.7 ± 6.3 kg/m2) ranged from 22.2 to 296.5 µmol/l. Median fasting ß-hydroxybutyrate levels were not different between women with high (median [IQR] 68.4 [49.1-109.2 µmol/l]) and low (65.4 [43.6-138.0 µmol/l]) carbohydrate intake in pregnancy. Fasting ß-hydroxybutyrate levels were not correlated with habitual carbohydrate intake (median 155 [126-189] g/day). The only metabolic parameter with which fasting ß-hydroxybutyrate levels were correlated was 1 h venous plasma glucose (ρ=0.23, p=0.03) during a 75 g OGTT. CONCLUSIONS/INTERPRETATION: Fasting serum ß-hydroxybutyrate levels are not associated with habitual carbohydrate intake at 28 weeks' gestation in pregnant women with overweight and obesity.

Prevalence and risk factors for hypercalcemia among non-dialysis patients with chronic kidney disease-mineral and bone disorder.

PURPOSE: To examine the prevalence and risk factors for hypercalcemia among non-dialysis chronic kidney disease (CKD) patients with mineral and bone disorder (MBD). METHODS: A retrospective cohort study was conducted in Singapore General Hospital, involving all CKD stage 4 and 5 pre-dialysis patients who were on treatment for MBD in June 2016. Each patient was followed up for 1 year and screened for hypercalcemia episodes. Mild, moderate and severe hypercalcemia were defined as corrected calcium of 2.47-3.00, 3.01-3.50 and ≥ 3.51 mmol/l respectively. Patients who were on dialysis, post-renal transplant, post-parathyroidectomy or had no calcium levels taken during the study period were excluded. Details related to patients' clinical information and hypercalcemia episodes were collected. Multivariate logistic regression analysis was performed to evaluate risk factors for hypercalcemia. RESULTS: Of 557 patients, 75 (13.4%) patients developed hypercalcemia. There were 120 (97.6%) mild and 3 (2.4%) moderate hypercalcemia episodes. The daily elemental calcium intake from phosphate binders and usage of vitamin D analogues did not differ between patients with and without hypercalcemia (p > 0.05). After adjusting for covariates, lower baseline iPTH level [odds ratio (OR) 0.96, 95% CI 0.93-0.99], history of hypercalcemia in past 1 year (OR 11.11, 95% CI 3.36-36.75) and immobility (OR 3.34, 95% CI 1.34-8.40) were associated with increased hypercalcemia risk. CONCLUSION: Hypercalcemia affects a significant proportion of pre-dialysis patients with MBD. More studies should be undertaken to evaluate other risk factors associated with hypercalcemia.