Summary Mean platelet volume (MPV) is increased in patients with coronary heart disease or at risk for stroke. However, MPV determinants have never been assessed in a population study. The present investigation is a cross-sectional study involving 366 non-selected subjects (both sexes, mean age 72.9 ± 5.5 [1 SD] years). The main cardiovascular risk factors, several indexes of adiposity (including percent body fat as estimated by skinfold measurement, and ultrasound detection of hepatic steatosis and thickness of abdominal subcutaneous and visceral fat) and ischaemic electrocardiographic (ECG) changes were assessed in all subjects. Platelet parameters were determined by a Bayer ADVIA 120 counter. In addition to being associated directly with platelet distribution width (PDW) and inversely with platelet count (p<0.0001 for both), MPV values were associated with subcutaneous abdominal fat (p=0.02), fasting blood glucose (p=0.002) and the prevalence of ischaemic ECG changes (p=0.004), and tended to be higher in the subjects with a greater prevalence of hepatic steatosis (p=0.07) and higher Homeostasis Model Assessment (HOMA) index (p=0.09). In multiple logistic regression, of the non-platelet parameters only percent body fat (p=0.006), ischaemic ECG changes (p=0.01) and blood glucose (p=0.03) remained independently associated with an MPV ≥8.4 fl (high tertile). The relative risk (odds ratio) of having ischaemic ECG changes for the subjects with MPV ≥8.4 fl was 4.2 (95% confidence interval: 2.5–7.1; p=0.006) with respect to the subjects with lower MPV values. Blood glucose, percent body fat and ischaemic ECG changes were the main MPV determinants in our elderly population.
This study was performed to ascertain the relative relevance of some inflammatory markers in insulin resistance.Four inflammatory markers (leukocyte count, erythrocyte sedimentation rate [ESR], high-sensitivity C-reactive protein [CRP], and C3 complement) were assessed as possible determinants of the homeostasis model assessment (HOMA) index, together with the five elements of the metabolic syndrome (National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults [Adult Treatment Panel III] definition), total cholesterol, physical activity, and four indicators of adiposity (BMI, waist circumference, percent body fat, and hepatic steatosis) in an unselected population of 990 subjects aged 65-91 years (the Pianoro Study).In univariable analysis, C3, CRP, and leukocyte count, but not ESR, were significantly correlated with HOMA index. In multivariable analysis, C3 remained associated with insulin resistance with the highest partial R(2) value (0.049), independently of all other covariates. The other most significant (P < 0.0001) determinants of HOMA index were total cholesterol (inverse association, R(2) = 0.026), waist circumference (R(2) = 0.023), triglycerides (R(2) = 0.022), and hepatic steatosis (R(2) = 0.021) (R(2) = 0.450 for the whole model). The adjusted relative risks of having the metabolic syndrome for the subjects with inflammatory markers in the high tertile, with respect to those with lower values, were (prevalence ratio [95% CI]): 1.77 (1.41-2.22) for C3, 1.38 (1.12-1.70) for leukocyte count, 1.17 (0.94-1.46) for CRP, and 1.13 (0.91-1.40) for ESR.Of the four inflammatory markers simultaneously assessed in our elderly population, only C3 was strongly associated with insulin resistance, independently of the components of the metabolic syndrome and the main indexes of abdominal and general obesity.
