BackgroundLow vitamin D status has been linked to an increased risk for various inflammatory diseases. Conflicting results have been reported regarding chronic obstructive pulmonary disease (COPD). This study aims to investigate the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with COPD risk and survival.MethodsWe included 403 648 participants with serum 25(OH)D measurements and free of COPD at baseline from UK Biobank. Follow-up was until 30 September 2021. Multivariable-adjusted cox regression models were applied to estimate HRs and 95% CIs for the associations of season-standardised 25(OH)D concentrations with COPD risk and survival. The restricted cubic splines were used to assess dose–response relationship. Kaplan-Meier estimation was used to create graphs of the survival curves.ResultsDuring a median follow-up of 12.3 (IQR: 11.4–13.2) years, 11 008 cases of COPD were recorded. We observed a non-linear inverse association between 25(OH)D concentrations and COPD risk. Compared with participants in the fourth quintile of 25(OH)D, those in the lowest quintile were associated with a 23% higher risk (HR, 1.23; 95% CI, 1.16 to 1.31). Stronger associations were observed for the risk in men and current smokers (Both p for interaction <0.05). In survival analyses, compared with the fourth quintile, cases in the lowest quintile had a 38% higher risk for overall death (HR, 1.38; 95% CI, 1.22 to 1.56).ConclusionOur findings indicate that serum 25(OH)D concentrations are non-linearly negatively associated with incidence and mortality of COPD, suggesting a potential protective role of vitamin D in the pathogenesis of COPD.

ObjectiveTo investigate the associations of circulating liver function marker levels with the risk of chronic obstructive pulmonary disease (COPD).MethodsWe leveraged the data of 372,056 participants from the UK Biobank between 2006 and 2010. The assessed circulating liver function markers included alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total bilirubin (TBIL), albumin (ALB), and total protein (TP). Incident COPD was identified through linkage to the National Health Service registries. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsDuring a median follow-up period of 12.3 (interquartile range:11.4-13.2) years, we documented 10,001 newly diagnosed COPD cases. Lower levels of ALT, TBIL, ALB, and TP and higher levels of GGT and ALP were nonlinearly associated with elevated COPD risk. The HR (95% CI) for decile 10 vs. 1 was 0.92 (0.84-1.01) for ALT, 0.82 (0.75-0.89) for TBIL, 0.74 (0.67-0.81) for ALB, 0.96 (0.88-1.04) for TP, 1.45 (1.31-1.62) for GGT, and 1.31 (1.19-1.45) for ALP. Restricted cubic spline analyses suggested a U-shaped relationship between AST levels and COPD risk (P for nonlinearity &lt;0.05).ConclusionWe observed that all seven circulating liver function markers were nonlinearly associated with the risk of COPD, indicating the importance of liver function in COPD.

Aim: To investigate the associations of diabetes, prediabetes and diabetes duration with chronic obstructive pulmonary disease (COPD) risk and survival in the UK Biobank. Materials and Methods:We conducted a prospective analysis among 452 680 participants without COPD at baseline using UK Biobank data. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated from Cox regression models. The dose-response relationship was explored using restricted cubic splines. A separate survival analysis was conducted for 12 595 patients with incident COPD.Results: Over a median follow-up of 12.3 years, 12 595 cases of COPD were documented. Compared with the reference group, those with prediabetes and diabetes were associated with an 18% (HR 1.18 [95% CI: 1.13-1.24]) and 35% (HR 1.35 [95% CI: 1.24-1.47]) higher risk of COPD, respectively. Diabetes duration was associated with COPD risk, with multivariable HRs (95% CIs) of 1.23 (1.05-1.44), 1.20 (1.04-1.39) and 1.18 (1.01-1.37) for diabetes duration of 7 years or longer, 3 to less than 7 years, and 1 to less than 3 years versus less than 1 year, respectively. Doseresponse analysis revealed a non-linear relationship between diabetes duration and COPD risk. Regarding COPD survival, COPD patients with prediabetes and diabetes had a 9% (HR 1.09 [95% CI: 1.00-1.19]) and 21% (HR 1.21 [95% CI: 1.05-1.41]) higher risk of overall death, respectively. Compared with the cases with a diabetes duration of less than 1 year, those with a diabetes duration of 7 years or longer were associated with a 46% higher risk of overall death ).