Increase in serum resistin during weight loss in overweight subjects is related to lipid metabolism.

OBJECTIVE: Human resistin has been stated to influence preadipocyte cell numbers and to stimulate adipocyte triglyceride lipolysis in vivo and in vitro. However, its role in human obesity remains unclear. DESIGN: Cross-sectional study for comparisons of lean and obese subjects, and subsequent longitudinal 4-month weight loss intervention study in obese subjects. SUBJECTS: Healthy subjects, lean (n=20, BMI<25) and overweight (n=43, BMI>or=25). MEASUREMENTS: Serum resistin, body weight, body fat, waist-to-hip ratio, as well as markers of insulin resistance and lipid metabolism at baseline and after 4 months of intervention. RESULTS: Serum resistin was positively correlated to HOMA-IR (partial r=0.288; P=0.055), serum fructosamines (partial r=0.280; P=0.062), serum NEFA (partial r=0.276; P=0.066) and negatively to age (partial r=-0.349; P=0.019) and serum apolipoprotein A-1 (partial r=-0.363; P=0.014). During the intervention, serum resistin increased significantly (P<0.001). The increase was inversely related to changes in waist-to-hip ratio (P=0.025) and positively to serum apolipoprotein B (P=0.011). In males only, the increase in resistin during weight loss was predicted by total serum cholesterol at baseline (r=0.703, P=0.007). No relation was observed between changes in resistin and changes in HOMA-IR. CONCLUSION: The present study indicates an association between serum resistin and markers of abdominal fat distribution as well as the regulation of lipid metabolism. However, human resistin is unlikely to play an independent role in the regulation of glucose metabolism.

An easy-to-use semiquantitative food record validated for energy intake by using doubly labelled water technique.

BACKGROUND: Estimating dietary intake is important for both epidemiological and clinical studies, but often lacks accuracy. OBJECTIVE: To investigate the accuracy and validity of energy intake estimated by an easy-to-use semiquantitative food record (EI(SQFR)) compared to total energy expenditure (TEE) estimated by doubly labelled water technique (EE(DLW)). DESIGN: TEE was measured in 29 nonobese subjects using the doubly labelled water method over a period of 14 days. Within this period, subjects reported their food consumption by a newly developed semiquantitative food record for 4 consecutive days. Energy intake was calculated using the German Food Code and Nutrition Data Base BLS II.3. RESULTS: A good correlation was observed between EI(SQFR) and EE(DLW) (r = 0.685, P < 0.001). The mean difference between EI(SQFR) and EE(DLW) was -1.7+/-2.6 MJ/day (-14+/-21%, P = 0.002). An underestimation of EI(SQFR) <10% was observed in nine subjects (31%), of 10-20% in six subjects (21%), and of >20% in nine subjects (31%). In five subjects (17%), an overestimation of EI(SQFR) was observed. CONCLUSIONS: The easy-to-use semiquantitative food record provided good estimates of EI in free-living and nonobese adults without prior detailed verbal instructions. The presented food record has limitations regarding accuracy at the individual level.

Validation of a simplified physical activity record by doubly labeled water technique.

INTRODUCTION: For obtaining reliable information about physical activity in epidemiological studies, validated and easy-to-use instruments are required. Therefore, a new simplified physical activity record based on 15-min recording intervals was developed and validated. SUBJECTS: Nonobese volunteers (n = 31). MEASUREMENTS: Physical activity was recorded over a 7-day period without detailed instructions. Energy expenditure was calculated (EE(sPAR)) and compared to energy expenditure measured by doubly labelled water technique (EE(DLW)). RESULTS: A good agreement between EE(sPAR) (12.1+/-3.0) and EE(DLW) (11.7+/-3.3) with a mean difference of 0.33+/-1.55 MJ (r = 0.880, P < 0.001) was observed. The absolute difference between EE(sPAR) and EE(DLW) was < 10% in 65% of the subjects. The difference between EE(sPAR) and EE(DLW) was independent of gender, age, body weight, and body mass index. A weak positive association between the difference and total body fat was observed (r = 0.618, P < 0.001), suggesting a slight tendency to overestimate EE(sPAR) with increasing total body fat. CONCLUSION: The new simplified physical activity protocol needs no detailed instructions, provides valid estimates of physical activity in nonobese free-living adults and can be used in epidemiological studies to assess total daily energy expenditure and physical activity level.

[Body build related body composition and nutrition in adulthood--a comparison of skinfold thickness measurement and bioelectric impedance analysis]. / Körperbautypspezifische Körperzusammensetzung und Ernährung im Erwachsenenalter--ein Vergleich von Hautfaltendickenmessung und bioelektrischer Impedanzanalyse.

The objective of the present study was to conduct a comprehensive analysis of body build, body composition and nutritional status. The study sample consists of 498 men and women aged from 35 to 65 years. Subjects underwent a detailed anthropometric examination incompassing thirty-one body measurements, eleven skinfold thickness measurements, and bioelectrical impedance analysis for determination of body composition. Dietary intake was assessed by a semiquantitative food frequency questionnaire. Body composition was clearly associated with age and body build. Somatometric differentiation by use of the metric index showed that percentage of body fat was significantly higher in pycnomorphic compared to leptomorphic subjects, whereas reported dietary energy intake was lower. Comparison of estimates of body fat showed considerably deviating results for skinfold thickness measurements and bioelectrical impedance analysis depending on the equations used. This was especially pronounced in obese subjects, where, on an average, bioelectrical impedance analysis resulted in higher values for percentage of body fat compared to skinfold thickness measurements. We conclude that for assessment of nutritional status body composition should be investigated taking into account body build in addition to age and sex.

Physique and body composition: comparisons of methods and results.

Body mass is the most investigated measurement for the evaluation of the nutritional and health status of children and adults. To apply it requires consideration of its correlations with sex, height and age, and if possible the type of body shape. It requires also the consideration of body composition, in particular the total body fat content. Here a problem arises. While classic anthropometric techniques are suitable for field investigations with large samples, the investigation of body composition needs the highly technical equipment of a laboratory as a rule. Based on a representative sample of 21,648 males and 21,391 females from all the new federal states of Germany this paper tries to find easily obtained anthropometric measurements which are usable for a type specific estimation of body composition under field conditions. For this reason body mass by sex and height is classified by three different concepts: the skeletal concept with categories of frame size, estimated by the frame index, the whole body concept with categories of corpulence, estimated by the metric index, and the fat concept with categories of subcutaneous fat layer thicknesses. Focussing on a type-specific body mass by height for an assessment of the nutritional status, the skeletal concept is proved to be the best. The summary of body mass and height by the body mass index (BMI), measured in kg/m2, gives the possibility of bringing two measurements into one dimension and to leave the second dimension free for the important variable of age. BMI by sex, age and frame type is found to be a good and practical instrument for the assessment of the nutritional and health status.

Body composition, nutrition and nutritional habits of young and elderly adults.

After the unification of East and West Germany the living conditions and the nutritional habits of the East German population changed considerably. The effects of these changes on nutritional status, physique and body composition are examined by a comparison of the representative sample of Greil taken from the East German population before the reunification of Germany with the sample of Trippo measured in the East German town of Potsdam between 1995 and 1997. The comparison of the samples of Greil and Trippo gives no indication of any increase in overweight subjects or adiposity during the last few years amongst the older test persons. However, the body mass of younger subjects shows a slight increase. Comparison of the estimates of total body fat showed considerable variation in results for skinfold thickness measurements and bioelectrical impedance analysis depending on the formula used.