Differences in vitamin D concentration between metabolically healthy and unhealthy obese adults: Associations with inflammatory and cardiometabolic markers in 4391 subjects

AimThis study aimed to compare concentrations of serum 25-hydroxy vitamin D and inflammatory markers in metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO), and to determine whether the relationship between vitamin D levels and both cardiometabolic and inflammatory markers differs between MHO and MUO.MethodsThis cross-sectional study comprised 4391 obese subjects aged > 18 years. A panel of cardiometabolic and inflammatory markers, including anthropometric variables, glycaemic indices, lipid profiles, liver enzymes, homocysteine, C-reactive protein (CRP), fibrinogen and serum 25-hydroxy vitamin D levels, was investigated. All cardiometabolic and inflammatory markers in MHO and MUO as well as in vitamin D deficiency were compared.ResultsPrevalence of MHO was 41.9% in our obese subjects using International Diabetes Federation criteria. Considering insulin resistance and inflammation, the prevalence of MHO was 38.4%. Individuals with MHO had significantly higher vitamin D concentrations compared with MUO, and this difference in vitamin D status persisted after accounting for BMI and waist circumference. Subjects with MHO had significantly better metabolic status, lower liver enzymes, lower inflammatory markers and higher serum 25-hydroxy vitamin D than those with MUO. Associations between vitamin D levels and inflammatory and cardiometabolic markers differed according to MHO/MUO status. Among MUO subjects, vitamin D deficiency was associated with higher liver marker and homocysteine levels. Serum vitamin D was negatively associated with fasting plasma glucose and HbA_1c in MHO only.ConclusionSerum 25-hydroxy vitamin D levels were lower in MUO vs MHO, and reduced vitamin D concentrations were more strongly associated with cardiometabolic and inflammatory markers in MUO than in MHO subjects. These findings suggest that a deficiency in vitamin D could be a key component of MUO.     

Usefulness of the plasma glucose concentration-to-HbA1c ratio in predicting clinical outcomes during acute illness with extreme hyperglycaemia

AimsTo evaluate the correlation between the plasma glucose-to-glycated haemoglobin ratio (GAR) and clinical outcome during acute illness.MethodsThis retrospective observational cohort study enrolled 661 patients who visited the emergency department of our hospital between 1 July 2008 and 30 September 2010 with plasma glucose concentrations > 500 mg/dL. Systolic blood pressure, heart rate, white blood cells, neutrophils, haematocrit, blood urea nitrogen, serum creatinine, liver function and plasma glucose concentration were recorded at the initial presentation to the emergency department. Data on glycated haemoglobin over the preceding 6 months were reviewed from our hospital database. The glucose-to-HbA_1c ratio (GAR) was calculated as the plasma glucose concentration divided by glycated haemoglobin.ResultsThe GAR of those who died was significantly higher than that of the survivors (81.0 ± 25.9 vs 67.6 ± 25.0; P < 0.001). There was a trend towards a higher 90-day mortality rate in patients with higher GARs (log-rank test P < 0.0001 for trend). On multivariate Cox regression analysis, the GAR was significantly related to 90-day mortality (hazard ratio [HR] for 1 standard deviation [SD] change: 1.41, 95% confidence interval [CI]: 1.22–1.63; P < 0.001), but not to plasma glucose (HR: 0.89, 95% CI: 0.70–1.13; P = 0.328). Rates of intensive care unit (ICU) admission and mechanical ventilator use were also higher in those with higher GARs.ConclusionGAR independently predicted 90-day mortality, ICU admission and use of mechanical ventilation. It was also a better predictor of patient outcomes than plasma glucose alone in patients with extremely high glucose levels.