The yield of early-pregnancy homeostasis of model assessment -insulin resistance (HOMA-IR) for predicting gestational diabetes mellitus in different body mass index and age groups.

BACKGROUND: Early prediction of gestational diabetes mellitus(GDM) can be beneficial for lifestyle modifications to prevent GDM. The aim of this study was to investigate the predictive values of Homeostasis of Model Assessment -Insulin Resistance (HOMA-IR) in early pregnancy to predict GDM development in different body mass index (BMI) and age risk categories. MATERIALS AND METHODS: This study is part of the Qazvin Maternal and Neonatal Metabolic Study (QMNMS) in Iran (2018-2021). In this prospective longitudinal study, pregnant women with a gestational age ≤ 14 weeks were enrolled in the study using convenience sampling method and were followed up until delivery to investigate risk factors for maternal and neonatal complications. Data collection was done using questionnaires. Serum sampling was done at a gestational age ≤ 14 weeks and sera were frozen until the end of study. GDM was diagnosed at 24-28 weeks of pregnancy using 75gr oral glucose tolerance test. Fasting blood glucose and insulin were measured in sera taken during early pregnancy in 583 participants. The Mann-Whitney U test, independent t-test, and Chi-square test were used for comparing variables between groups. The logistic regression analysis was used to examine the independent association of HOMA-IR with GDM development and receiver operating characteristic analysis was used for finding the best cut-off of HOMA-IR for predicting GDM. RESULTS: GDM was developed in 90 (15.4%) of the participants. The third HOMA-IR tertile was independently associated with 3.2 times higher GDM occurrence (95% CI:1.6-6.2, P = 0.001). Despite the high prevalence of GDM in advanced maternal age (GDM rate = 28.4%), HOMA-IR had no association with GDM occurrence in this high-risk group. In both normal BMI and overweight/obese groups, HOMA-IR was a moderate predictor of GDM development (AUC = 0.638, P = 0.005 and AUC = 0.622, P = 0.008, respectively). However, the best cut-off for predicting GDM was 2.06 (sensitivity 67.5%, specificity 61.1%) in normal BMI and 3.13 (sensitivity 64.6%, specificity61.8%) in overweight/obese BMI. CONCLUSION: The present study revealed the necessity of considering the BMI and age risk groups when using the HOMA-IR index to predict GDM. Using lower cut-offs is more accurate for women with a normal BMI. In the advanced maternal age, there is no yield of HOMA-IR for predicting GDM.

Association of weekly or biweekly use of 50 000 IU vitamin D3 with hypervitaminosis D.

Since the beginning of the COVID-19 pandemic, many Iranian people have been taking 50 000 IU of vitamin D3 on weekly or biweekly bases in order to enhance their immune system function. This cross-sectional study was conducted on the patients of endocrinology clinic to compare 25(OH)D levels of weekly or biweekly consumption with the monthly users of vitamin D3 50 000 IU. The level >100 ng/mL of 25(OH)D was defined as hypervitaminosis D. In total, 211 patients (108 and 103 patients in monthly and weekly/biweekly groups, respectively) were studied. In the subgroups of weekly and biweekly users, the rates of hypervitaminosis were 18.9% and 4.5%, respectively. In contrast, only 0.9% of monthly users had hypervitaminosis D. The highest vitamin D value of 185 ng/mL was detected in a patient who had consumed 50 000 IU vitamin D3 weekly for 6 years. No hypercalcaemia was detected in patients with hypervitaminosis D.