Prevalence of Subclinical Hypothyroidism in Chronic Kidney Disease in a Population-based Study: Tehran Thyroid Study

Background: Chronic kidney disease (CKD) is a rising public health concern that has detrimental effects on cardiovascular health and overall survival. Subclinical hypothyroidism (SCH) has been associated with poor outcomes in the general population. It is thought to be more prevalent in CKD subjects, and their coexistence may contribute to poor outcomes in these patients. We aimed to determine the prevalence of SCH in CKD. Methods: Using data from the Tehran thyroid study, which is a prospective population-based cohort study, adult subjects with an estimated Glomerular Filtration Rate (eGFR) of 60 mL/min/1.73 m2 or less were selected for studying the prevalence of thyroid abnormalities, as well as other known cardiovascular risk factors. Results: Of 5,626 subjects recruited, 823 (14.6) individuals had CKD. Individuals with CKD were older, heavier, had a higher prevalence of diabetes, higher serum thyrotropin, and thyroid peroxidase anti-body levels, but lower free thyroxine levels. The prevalence of SCH was 7.3 and 5.2 (P < 0.001) in kidney disease and non-kidney disease subjects, respectively. However, there was no difference in the risk of SCH between CKD and non-CKD subjects after adjustment for age, sex, BMI, smoking, and TPOAb (OR: 1.28; 95CI, 0.89 - 1.83). None of the metabolic markers compared between the CKD subgroups of those with and without SCH remained statistically significantly different after adjusting for age and gender. Conclusions: The prevalence of SCH was not higher in CKD after controlling for confounding factors. Besides, CKD subjects with and without SCH had no different metabolic parameters. © 2021, International Journal of Endocrinology and Metabolism

Fine-structure diagnostics of neutral carbon toward HE 0515-4414

New high-resolution high signal-to-noise spectra of the $z=1.15$ damped Lyman $\alpha$ (DLA) system toward the quasi-stellar object HE 0515-4414 reveal absorption lines of the multiplets 2 and 3 in \ion{C}{i}. The resonance lines are seen in two components with total column densities of $\log N=13.79\pm0.01$ and $\log N=13.36\pm0.01$, respectively. The comparision of theoretical calculations of the relative fine-structure population with the ratios of the observed column densities suggests that the \ion{C}{i} absorbing medium is either very dense or exposed to very intense UV radiation. The upper limit on the local UV energy density is 100 times the galactic UV energy density, while the upper limit on the \ion{H}{i} number density is 110 cm$^{-3}$. The excitation temperatures of the ground state fine-structure levels of $T=15.7$ and $T=11.1$ K, respectively, are consistent with the temperature-redshift relation predicted by the standard Friedmann cosmology. The cosmic microwave background radiation (CMBR) is only a minor source of the observed fine-structure excitation.Comment: 5 pages, 5 figures, uses A&A macro package, gzipped tar archive, accepted by A&

High Hemoglobin A1c levels and glycemic variability increase risk of severe hypoglycemia in diabetic hemodialysis patients

While hyperglycemia is central to the pathogenesis and management of diabetes mellitus, hypoglycemia and glucose variability also contribute to outcomes. We previously reported on the relationship of glycemic control to outcomes in a large population of diabetic end-stage renal disease (ESRD) patients. Recognizing that ESRD is a risk factor for severe hypoglycemia, we have now analyzed the association between glycosylated hemoglobin A1c (HgbA1c) levels and glycemic variability in those with hypoglycemia. This is a retrospective study of patients with diabetes enrolled in a large hemodialysis program. Hypoglycemia was identified from hospital discharge diagnostic codes. Glycemic variability was assessed by the standard deviation of HgbA1c and glucose levels over time. Hypoglycemia as a discharge diagnosis was documented in 4.1% of patients. Higher baseline HgbA1c was associated with greater risk for hypoglycemia hospitalization, a finding confirmed by time-lagged HgbA1c levels drawn a quarter earlier. Higher baseline HgbA1c categories were also associated with greater variability in HgbA1c levels during the analysis period. Similarly, greater glucose variability was associated with higher mean glucose levels by trend analysis. High, not low, HgbA1c levels are associated with greater risk of severe hypoglycemia, which may derive from glucose variability in the setting of treatment for hyperglycemia. High HgbA1c and glycemic variability are associated with increased risk of hypoglycemia in individuals with diabetes and ESRD