The association between vitamin D levels and metabolic syndrome components among metropolitan adolescent population

Objectives Vitamin D promotes both lipolysis and lipogenesis, and some pediatric studies showed inconsistent associations between vitamin D and metabolic syndrome (MetS). This cross-sectional study aimed to examine the association between vitamin D levels and MetS components among metropolitan adolescents. Methods A total of 4,149 adolescents aged 10–18 years were recruited from 23 metropolises in China. The MetS conditions were assessed according to the International Diabetes Federation consensus definition, and the serum 25-hydroxy vitamin D (25(OH)D) concentrations were analyzed. The association between MetS components and serum 25(OH)D levels was analyzed by the logistic regression model. Restricted cubic spline was applied to the model nonlinear association. Results Prevalence of vitamin D deficiency was 74.9%, and 41.2% of study participants had at least one MetS component. After adjustment, the significant trend for a lower waist-to-height ratio was not observed in study participants with higher serum 25(OH)D quartile (p=0.57), but a significant nonlinear association between abdominal obesity and serum 25(OH)D levels was found (p=0.04): the highest risk of abdominal obesity occurred at 14.1 ng/mL of serum 25(OH)D. The association of serum 25(OH)D was significantly inverse with MetS (OR: 0.95; 95% CI: 0.92–0.98), but not with raised triglycerides (OR: 0.99; 95% CI: 0.96–1.01), raised blood pressure (OR: 0.99; 95% CI: 0.97–1.01) and impaired fasting glycemia (OR: 1.03; 95% CI: 1.01–1.04). Conclusions The net effect of vitamin D on lipid metabolism may be concentration-dependent, and the actual effect of vitamin D on MetS process may be complex among metropolitan adolescents, though serum 25(OH)D is inversely associated with MetS.

The Effects of Calculated Remnant-Like Particle Cholesterol on Incident Cardiovascular Disease: Insights from a General Chinese Population

Background: Growing evidence suggests that remnant cholesterol (RC) contributes to residual atherosclerotic cardiovascular disease (ASCVD) risk. However, the cutoff points to treat RC for reducing ASCVD are still unknown. This study aimed to investigate the relationships between RC and combined cardiovascular diseases (CVDs) in a general China cohort, with 11,956 subjects aged ≥ 35 years. Methods: Baseline RC was estimated with the Friedewald formula for 8782 subjects. The outcome was the incidence of combined CVD, including fatal and nonfatal stroke and coronary heart disease (CHD). The Cox proportional hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals. The restricted cubic spline (RCS) model was used to evaluate the dose–response relationship between continuous RC and the natural log of HRs. Results: After a median follow-up of 4.66 years, 431 CVD events occurred. In the Cox proportional models, participants with a high level of categorial RC had a significantly higher risk for combined CVD (HR: 1.37; 95% CI: 1.07–1.74) and CHD (HR: 1.63; 95% CI: 1.06–2.53), compared to those with a medium level of RC. In the stratification analyses, a high level of RC significantly increased combined CVD risk for subgroups females, age < 65 years, noncurrent smokers, noncurrent drinkers, normal weight, renal dysfunction, and no hyperuricemia. The same trends were found for CHD among subgroups males, age < 65 years, overweight, renal dysfunction, and no hyperuricemia; stroke among subgroup females. In RCS models, a significant linear association between RC and combined CVD and a nonlinear association between RC and CHD resulted. The risk of outcomes was relatively flat until 0.84 mmol/L of RC and increased rapidly afterwards, with an HR of 1.308 (1.102 to 1.553) for combined CVD and 1.411 (1.061 to 1.876) for CHD. Stratified analyses showed a significant nonlinear association between RC and CVD outcomes in the subgroup aged < 65 years or the diabetes subgroup. Conclusions: In this large-scale and long-term follow-up cohort study, participants with higher RC levels had a significantly worse prognosis, especially for the subgroup aged 35–65 years or the diabetes mellitus subgroup.

Development of a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma: a retrospective cohort study

Objective To develop and validate a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma (PA). Methods This retrospective cohort study included 205 patients with PAs between January 2013 and April 2020 in the Sun Yat-sen Memorial Hospital, Guangzhou, China. The patients were randomly classified into either a training set (N = 143 patients) and a validation set (N = 62 patients) at a ratio of 7:3. Variables, which were identified by using the LASSO regression model were included for the construction of a nomogram, and a logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) in the training set. The area under the curve (AUC) was used to evaluate the performance of the nomogram for predicting hypokalemia. Multivariate logistic regression analysis with a restricted cubic spline analysis was conducted to identify a potential nonlinear association between the preoperative index and hypokalemia. Results The incidence of hypokalemia was 38.05%. Seven preoperative indices were identified for the construction of the nomogram: age, type of PA, weight, activated partial thromboplastin time, urea, eosinophil percentage, and plateletocrit. The AUCs of the nomogram for predicting hypokalemia were 0.856 (95% CI [0.796–0.915]) and 0.652 (95% CI [0.514–0.790]) in the training and validation sets, respectively. Restricted cubic splines demonstrated that there was no nonlinear association between hypokalemia and the selected variables. Conclusion In this study, we constructed a preoperative indices-based nomogram that can assess the risk of hypokalemia after the surgical treatment of pituitary adenomas. This nomogram may also help to identify high risk patients who require close monitoring of serum potassium.

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association—A Systematic Review and Meta-analysis

Background and Purpose Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28–1.61) per 5 µmol/L increase in Hcy levels. Conclusion This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study.This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

A nonlinear association of total cholesterol with all-cause and cause-specific mortality

Background The link between total cholesterol (TC) and all-cause and specific mortality has not been elucidated. Herein, we aimed to evaluate the effect of TC levels on all-cause, cardiovascular disease (CVD), and cancer mortality. Methods All data analyzed were obtained from the National Health and Nutrition Examination Survey 1999–2014. The relationship between levels of TC and mortality was determined through Cox proportional hazard regression analysis coupled with multivariable adjustments. Two-piecewise linear regression models and Cox models with penalized splines were applied to explore nonlinear and irregular shape relationships. Kaplan–Meier survival curve and subgroup analyses were conducted. Results The sample studied comprised 14,662 men and 16,025 women, categorized as 25,429 adults aged 18–65 and 5,258 adults over 65 years old. A total of 2,570 deaths were recorded. All-cause, cardiovascular, and cancer mortality showed U-curve associations after adjusting for confounding variables in the restricted cubic spline analysis. Hazard ratios (HRs) of all-cause and cancer mortality were particularly negatively related to TC levels in the lower range < 200 mg/dL, especially in the range < 120 mg/dL (HR 1.97; 95% CI 1.38, 2.83, HR 2.39; 95% CI 1.21, 4.71, respectively). However, the HRs of cardiovascular disease mortality in the range < 120 mg/dL were the lowest (HR 0.60; 95% CI 0.15, 2.42). In the upper range, a TC range of ≥ 280 mg/dL was correlated with mortality as a result of CVD and cancer (HR 1.31; 95% CI 0.87, 1.97 and HR 1.22; 95% CI 0.82, 1.79). The lowest cumulative survival rate of all-cause mortality was recorded in the lowest TC-level group, while the lowest cumulative survival rate of CVD mortality was recorded in the highest TC-level group. Conclusions A nonlinear association of TC level with all-cause, cancer, and CVD mortality in the American population was observed, suggesting that too low or too high serum total cholesterol levels might correlate with adverse outcomes.