P Lührmann

Changes in resting metabolic rate in an elderly German population: Cross-sectional and longitudinal data

Background/ObjectivesThis study investigates age-dependent changes in resting metabolic rate (RMR) considering changes in body composition and fat distribution within the longitudinal study on nutrition and health status in an aging population in Giessen (GISELA), Germany, using three different approaches.Subjects/MethodsIn approach 1 cross-sectional data from 358 female and 155 male participants of the GISELA study were evaluated (mean age of 67.4 ± 5.9 and 66.9 ± 5.2 y, respectively). In approach 2 longitudinal data of 107 female and 55 male subjects who participated over a follow up period of 10 years were analysed. In approach 3 all data obtained at a total of 3033 visits from 363 women and 153 men between 1994 and 2006 were evaluated. The mean duration of follow-up was eight years. RMR was assessed by indirect calorimetry.ResultsApproach 1: RMR correlates significantly negatively with age in women and men. Considering fat free mass, fat mass, and WHR, age proved to be a significant predictor of RMR in both sexes in multiple regression analysis; RMR falls by 11.2 kJ/d and 34.1 kJ/d per year in females and males, respectively. Approach 2: In males but not in females RMR decreases significantly in the course of the follow up. After ten years measured RMR is significantly lower than expected RMR predicted on the basis of body composition and fat distribution in females and males. Deviations correspond to a decline in RMR by 11.4 and 27.5 kJ/d per year independently of changes in body composition and fat distribution. Approach 3: Results of the mixed linear model show that RMR decreases in the course of aging in both women and men; after considering changes in body composition and fat distribution respective decreases were 8.7 and 30.7 kJ/d per year.ConclusionsThese results indicate that the decline in RMR with advancing age cannot be totally due to changes in body composition.

Effect of Age on Plasma Homocysteine Concentrations in Young and Elderly Subjects Considering Serum Vitamin Concentrations and Different Lifestyle Factors

OBJECTIVES The aim of this study was to investigate whether an increase in total homocysteine (tHcy) concentration with increasing age is due to diminishing serum concentrations of pyridoxal-5-phosphate (PLP), vitamin B-12, and folate. The possible influence of different lifestyle factors on tHcy concentration was considered. METHODS Plasma tHcy, serum concentrations of pyridoxal-5-phosphate, vitamin B-12, and folate, intake of coffee and tea, alcohol, and methionine, as well as cigarette smoking, were determined in 252 elderly subjects (60-87 years old) of the longitudinal study on nutrition and health status in an aging population in Giessen (GISELA) and 99 young adults (20-34 years old) of the study on health and nutrition of young adults (GEJE). RESULTS Mean plasma tHcy concentrations were significantly higher in elderly than in young female subjects (9.7 +/- 1.9 micromol/L vs. 9.0 +/- 1.6 micromol/L, p < 0.05), but there was no difference between elderly and young men (10.6 +/- 2.1 micromol/L vs. 10.7 +/- 2.6 micromol/L). No differences in tHcy were observed between young and elderly subjects after adjustment for serum concentrations of PLP, vitamin B-12, and folate. Multiple linear regression analysis revealed a significant influence of age only in elderly, but not in younger subjects. CONCLUSION Higher tHcy concentrations in the elderly, in comparison to younger women, are due to lower serum concentrations of PLP, vitamin B-12, and folate, whereas within the age group of elderly subjects alone tHcy concentrations increase with age irrespective of serum vitamin concentrations.

Identifying Elderly Women with Osteoporosis by Spinal Dual X-ray Absorptiometry, Calcaneal Quantitative Ultrasound and Spinal Quantitative Computed Tomography: A Comparative Study

The ability of spinal dual x-ray absorptiometry (DXA), calcaneal quantitative ultrasound (QUS) and spinal quantitative computed tomography (QCT) to identify women with osteoporosis within the GISELA study was evaluated in 43 women, aged 62-87 years. Osteoporosis was defined as a T-score below or equal to -2.5 using DXA (femoral neck). To determine the performance of each method, the sensitivity, specificity and area under the curve (by means of a receiver operating characteristic [ROC] analysis) were calculated. The median T-scores from the measurements differed significantly (p < 0.0001). DXA (spine) identified 75% of women with osteoporosis; QUS and QCT identified 100%. The specificity was 89% for DXA (spine), 66% for QUS and 29% for QCT. ROC analysis showed that all three methods are qualified to identify women with osteoporosis; however, the different sensitivities and specificities of the methods, as well as the thresholds used for diagnosing osteoporosis have to be considered.

Vegetable consumption among university students: Relationship between vegetable intake, knowledge of recommended vegetable servings and self-assessed achievement of vegetable intake recommendations:

Objectives: To investigate the relationship between vegetable intake, knowledge of recommended vegetable servings and self-assessed achievement of vegetable intake recommendations. Design and setting: Cross-sectional nutritional study in a university setting. Method: Students answered a set of standardised questions. Vegetable intake was assessed using a food frequency questionnaire (FFQ). Knowledge of recommended vegetable servings was determined by asking how many servings of vegetables should be part of the daily diet. Self-assessed achievement of vegetable recommendation was operationalised using the behavioural stages of the Health Action Process Approach (HAPA). Results: Mean vegetable intake was 176 ± 165 g/day for women and 179 ± 153 g/day for men. Overall, 7.3% of women and 9.8% of men achieved the recommended vegetable intake. Recommended vegetable servings were correctly identified by 68.5% of women and 47.1% of men. About 34.1% of women and 23.5% of men believed they could achieve the recommended intake of vegetables. However, of these, only 18.7% and 33.3% actually achieved the recommended intake. These students did not differ with respect to their knowledge of recommended vegetable servings from those who stated they achieved the recommended intake but in fact did not. Conclusion: Our study identified a potential target group who did not know that their vegetable intake was below the recommended level. It may be concluded that students have difficulty correctly estimating amounts of vegetables. From a health promotion perspective, this creates the need for the practice-oriented communication of dietary recommendations.

Fluid Intake and Cognitive Performance: Should Schoolchildren Drink During Lessons?

BACKGROUND Evidence suggests that an insufficient fluid intake impairs cognitive performance. Drinking policies at schools-especially drinking during lessons-is a point of controversy. To provide a scientific base for this debate, more empirical evidence is needed on which aspects of fluid intake are crucial for cognitive performance. This study makes a contribution by investigating associations between quantitative and temporal aspects of fluid intake and cognitive performance in everyday school life. METHODS The study comprised 125 children (age: mean = 10.98 years, SD = 0.38). Amount of fluid intake and time span between fluid intake and completion of cognitive tests were determined on basis of self-reports. Cognitive performance was assessed by standardized tests. RESULTS Quantitative and temporal aspects were associated with cognitive performance: The more fluid the children consumed and the shorter the time span between their last fluid intake and test completion, the better they performed. CONCLUSIONS The amount of fluid intake should be adequate and moreover the time span between intake and cognitive efforts should be as short as possible. Schoolchildren are thus recommended to drink at regular intervals and also during lessons.