Low Vitamin D Levels Are Associated With Long COVID Syndrome in COVID-19 Survivors.

CONTEXT: Long COVID is an emerging syndrome affecting 50% to 70% of COVID-19 survivors that still lacks predicting factors. OBJECTIVE: Due to the extraskeletal effects of vitamin D, we retrospectively assessed the association between 25(OH) vitamin D levels and long COVID in COVID-19 survivors 6 months after hospitalization. METHODS: Long COVID was defined according to NICE guidelines. Fifty long COVID and 50 non-long-COVID subjects matched on a 1:1 basis were enrolled from an outpatient clinic post-COVID cohort seen from August to November 2020. Therapies/comorbidities affecting calcium/vitamin D/bone metabolism, and/or admission to the intensive care unit during hospitalization were exclusion criteria. 25(OH) Vitamin D was measured at hospital admission and 6 months after discharge. RESULTS: We observed lower 25(OH) vitamin D levels, evaluated at follow-up, in subjects with long COVID than those without (20.1 vs 23.2 ng/mL, P = .03). Regarding the affected health areas evaluated in the entire cohort, we observed lower 25(OH) vitamin D levels in those with neurocognitive symptoms at follow-up (n = 7) than those without (n = 93) (14.6 vs 20.6 ng/mL, P = .042). In patients presenting vitamin D deficiency (<20 ng/mL), both at admission and at follow-up (n = 42), those affected by long COVID (n = 22) presented lower 25(OH) vitamin D levels at follow-up than those not affected (n = 20) (12.7 vs 15.2 ng/mL, P = .041). In multiple regression analyses, lower 25(OH) vitamin D levels at follow-up were the only variable significantly associated with long COVID in our cohort (P = .008, OR 1.09, CI 1.01-1.16). CONCLUSION: COVID-19 survivors with long COVID have lower 25(OH) vitamin D levels than matched patients without long COVID. Our data suggest that vitamin D levels should be evaluated in COVID-19 patients after hospital discharge. The role of vitamin D supplementation as a preventive strategy of COVID-19 sequelae should be tested in randomized controlled trials.

Kidney function impairment in men with primary infertility: A case-control analysis.

BACKGROUND: Infertile men have a worse overall health status than their fertile counterparts. OBJECTIVE: We aimed to (1) compare kidney function in men presenting for primary couple's infertility with that of fertile men and (2) assess kidney function impairment toward sperm quality in infertile men. MATERIALS AND METHODS: In this case-control study, 387 consecutive white-European infertile men were matched by age with 134 same-ethnicity fertile men. Complete clinical and laboratory data were available for each patient. The Chronic Kidney Disease Epidemiology Collaboration function was used for estimated glomerular filtration rate calculation. Kidney functional impairment was defined as an estimated glomerular filtration rate <90 mL/min per 1.73 m2 , according to the Kidney Disease Improving Global Outcomes criteria. Multivariable logistic regression analysis was used to (1) assess the association between kidney function impairment and infertility status and (2) investigate the association between kidney function and semen analysis abnormalities in infertile men. RESULTS: After matching, 34 (8.8%) infertile men depicted at least a mild unknown impairment of kidney function compared to only four (3%) fertile men, with four (3%) of the infertile presenting with an overt kidney function impairment (estimated glomerular filtration rate <60 mL/min per 1.73 m2 ). There were no differences in terms of age, body mass index and rate of comorbidities between the two groups (all p > 0.05). After adjusting for major confounders, infertility status was associated with a higher risk of reduced estimated glomerular filtration rate (odds ratio 3.20; 95% confidence interval 1.21-5.2; p = 0.002). Conversely, estimated glomerular filtration rate was not associated with sperm abnormalities in infertile men. CONCLUSIONS: Mild kidney function impairment was found in 9% of asymptomatic and unaware men presenting for primary couple's infertility investigation. This novel finding corroborates growing data on a significant association of male infertility with a poorer overall male health status and the need for tailored preventive strategies.