The aim of the present study was to evaluate the recently defined simple insulin sensitivity check index QUICKI (Katz et al. 2000) for insulin resistance diagnostics in common clinical and epidemiological practice. Both the QUICKI (1/log insulin + log glycemia in mg/dL) and HOMA (insulin * glycemia in micromol/L/22.5) indexes were calculated from fasting values in 259 adult healthy volunteers and patients, and in 47 healthy and obese children of prepubertal age of both sexes. In adults, a fall in the QUICKI index (mean +/- SEM in healthy subjects = 0.366 +/- 0.029) as well as an increase in the HOMA index (in healthy subjects 1.57 +/- 0.87) corresponded to metabolic and clinical manifestations of insulin resistance in various groups of outpatients. The QUICKI index had lower dispersion variances and the 95% confidence limits displayed a higher discrimination capacity. Patients with glucose intolerance or diabetes, hyperlipidemia typical for insulin resistance, or with combination of these metabolic disorders were characterized by QUICKI index values that were significantly lower than those of healthy volunteers. The QUICKI index in healthy prepubertal children indicated a higher insulin resistance compared to adults (mean 0.339 +/- 0.020); an increase in the QUICKI index in obese children with BMI over 25 was not significant, although obese children showed a significant increase of serum leptin and triglycerides and a decrease of HDL-cholesterol. Adult patients with QUICKI index below 0.357 (which is at the lower limit of 95% confidence limits in healthy persons) represented a group with typical manifestations of metabolic syndrome, differing in these parameters significantly from the group of patients of comparable age with a QUICKI index greater than 0.357. The present study suggests suitability of the QUICKI index for diagnosis of insulin resistance in clinical and epidemiological practice. However, a normal QUICKI index range needs to be established for each laboratory with an appropriate control group because of significant interlaboratory variations in insulin determinations and/or possible differences in various populations.

Introduction:Cardiovascular disease (CVD) is the leading cause of death in developed countries. An integral part of primary prevention is physical activity. One form of physical activity to be potentially used is yoga, but this activity is associated with lower energy expenditure than that recommended for prevention. The study aimed at assessing the effect of regular yoga sessions on the aerobic capacity of the practitioners and comparing it with the normal population performing physical activity recommended by guidelines.Materials and Methods:Fifty-eight persons (16 males) with a mean age of 50.0 ± 11.06 years comprising the yoga group practiced yoga for at least 1 h a day for over 2 years. They underwent spiroergometry under maximal exercise testing to assess basic performance parameters. Their results were compared with those in 54 age-matched controls (16 males mean age of 48 ± 11.86 years performing a regular aerobic physical activity for at least 7 h a week.Results:The yoga group had statistically significantly higher maximum performance per kilogram (P = 0.007) and maximum oxygen consumption per kilogram per minute (P = 0.028).Conclusions:Despite low energy expenditure, yoga practices are better in some cardiorespiratory fitness parameters than other aerobic activities recommended by current guidelines for CVD prevention.

Key words: Obesity in children/Insulin resistance/Hypertension in children/HOMA/QUICKIBackground. Obesity and arterial hypertension are a serious risk factor for insulin resistance patients leading to diabetes and other disorders. Obesity is one of the most common nutritional problems in developed countries. Actually the incidence of obesity is increasing considerably, obesity is emerging in alarming rates between the last 10 years. Obesity and hypertension beginning in childhood often precedes the hyperinsulinemic state. The metabolic syndrome is rapidly increasing in prevalence with rising childhood obesity and sedentary lifestyles worldwide. The aim of this study was to compare average levels of the homeostatic indices HOMA and QUICKI in obese children compared to healthy and hypertonic children in order to find convenient markers for insulin sensitivity in clinical pediatric practice.Methods. 49 obese children (11 girls, 38 boys), 42 children healthy (33 boys and 9 girls) and 37 hypertensive children (4 girls, 33 boys) were selected.Results. The average level of HOMA in obese children was 4.58; in healthy children 1.8 and in the group of hypertonic children the level was 2.75. The average level of QUICKI in obese children was 0.22; in healthy children 0.29 and in hypertonic children 0.28.Conclusions. The results demonstrate the possibility of insulin sensitivity assessment using these indices in pediatric practice. QUICKI has a narrower confidence interval and thus a lower variability. QUICKI an HOMA indexes are useful predominantly for epidemiological purposes, mainly for maping the scope of insulinoresistance among children.gest that the prevalence of elevated blood pressure could have increased in children over the last few decades. Obesity itself needs not always mean overweight but an accumulation of fatty tissue. In childhood, it is obvious that the continuous increase in weight is not merely caused by the increase of fat tissue but also by the development of the body frame and the muscle mass. The share of this component differs according to the individual age group and gender.Obesity. One of the most common nutritional disorder worldwide, affecting virtually both developed and developing countries of all socio-economic groups, irrespective of age, sex or ethnicity, clearly associated with the metabolic syndrome, condition with implications for the development of many chronic diseases as obesity and hypertension, type 2 diabetes mellitus, dyslipidemia, obstructive sleep apnoe, and orthopedic problems. In the Czech Republic, childhood obesity is now a serious epidemiological problem: 20% of children aged 6-12 and 11% of children aged 13-17 years are already overweight or obese. These data were provided by the study of the Czech Obesity Association entitled "Life Style and INTRODUCTION

Common alimentary obesity frequently occurs on a polygenic basis as a typical lifestyle disorder in the developed countries. It is associated with characteristic complex metabolic changes, which are the cornerstones for future metabolic syndrome development. The aims of our study were 1) to determine the incidence of metabolic syndrome (based on the diagnostic criteria defined by the International Diabetes Federation for children and adolescents) in Czech obese children, 2) to evaluate the incidence of insulin resistance according to HOMA-IR and QUICKI homeostatic indexes in obese children with and without metabolic syndrome, and 3) to consider the diagnostic value of these indexes for the early detection of metabolic syndrome in obese children. We therefore performed anthropometric and laboratory examinations to determine the incidence of metabolic syndrome and insulin resistance in the group of 274 children with obesity (128 boys and 146 girls) aged 9-17 years. Metabolic syndrome was found in 102 subjects (37 %). On the other hand, the presence of insulin resistance according to QUICKI <0.357 was identified in 86 % and according to HOMA-IR >3.16 in 53 % of obese subjects. This HOMA-IR limit was exceeded by 70 % children in the MS(+) group, but only by 43 % children in the MS(–) group (p<0.0001). However, a relatively high incidence of insulin resistance in obese children without metabolic syndrome raises a question whether the existing diagnostic criteria do not falsely exclude some cases of metabolic syndrome. On the basis of our results we suggest to pay a preventive attention also to obese children with insulin resistance even if they do not fulfill the actual diagnostic criteria for metabolic syndrome.

The relatively high incidence of insulin resistance in obese children without MS questions the prevailing diagnostic criteria of, perhaps, falsely excluding some cases of, MS.