Petra M. Lührmann

Coffee Consumption and Total Body Water Homeostasis as Measured by Fluid Balance and Bioelectrical Impedance Analysis

To investigate the impact of coffee consumption on fluid balance, 12 healthy volunteers were supplied with a standardized diet for 2 days after having abstained from consumption of methylxanthines for 5 days. During the first day, fluid requirement was met by mineral water. On the following day the same amount of fluid was supplied and the mineral water was in part replaced by 6 cups of coffee containing 642 mg of caffeine. This led to an increase in 24-hour urine excretion of 753 +/- 532 ml (p < 0.001), a corresponding negative fluid balance and a concomitant decrease in body weight of 0.7 +/- 0.4 kg (p < 0.001). Total body water as measured with bioelectrical impedance analysis decreased by 1.1 +/- 1.2 kg or 2.7% (p < 0.01). Urinary excretion of sodium and potassium was elevated by 80 +/- 62 mmol or 66% (p < 0.01) and 14 +/- 12 mmol or 28% (p < 0.01), respectively.

Underreporting of Energy Intake in an Elderly German Population

OBJECTIVES Within the longitudinal study on nutrition and health status in an aging population in Giessen, Germany (GISELA), the underreporters of energy intake (EI) were identified and characterized. METHODS EI was assessed in 238 female and 105 male participants of the GISELA study (age range = 60-89 y) by means of a 3-day estimated dietary record developed especially for this study. Resting metabolic rate (RMR) was measured by indirect calorimetry after an overnight fast. EI was expressed as a multiple of RMR and subjects with an EI:RMR ratio below 1.073 were classified as underreporters. RESULTS Mean EI:RMR was 1.62 +/- 0.46 in females and 1.53 +/- 0.46 in males; 7.6% of the females and 16.2% of the males were identified as underreporters. They showed lower levels of education and significantly greater body weight, body mass index, and fat mass than the adequate reporters. Further, underreporters stated more often than adequate reporters that they want to lose weight. Except for beta-carotene in males, reported nutrient intakes were significantly lower in underreporters than in adequate reporters. Carbohydrate and fat intake in both sexes, protein intake in females calculated as a percentage of EI, and vitamin and mineral densities were not affected by underreporting. CONCLUSIONS The results indicate that underreporting of EI is related to a low educational level and greater body weight, body mass index, and fat mass and affects all nutrients. These findings should be considered when the association between nutrition and health status is investigated in the elderly.

Eight-year trends in food, energy and macronutrient intake in a sample of elderly German subjects.

Time trends in the food and the corresponding energy and macronutrient intake between 1994 and 2002 are investigated as part of the longitudinal study on nutrition and health status in an ageing population in Giessen, Germany (GISELA study). The dietary intake is assessed via a 3 d estimated dietary record especially developed and validated for this study. A total of 2135 records from 532 subjects, aged 60 years and over, are analysed separately according to sex and age groups (born 1904-1928 and born 1929-1942). Results show that the food, energy and macronutrient intake of the GISELA subjects stayed fairly stable over the study period. However, some significant changes in the consumption pattern are observed, predominantly in the women and the younger age groups, which correspond to the national trends in Germany. Most obvious changes observed among the GISELA subjects are the increased intake of water (between +21.05 and +41.61 ml/d per year) and vegetables (between +2.94 and +3.38 g/d per year) and a reduced consumption of coffee and tea (between -10.65 and -15.99 ml/d per year) as well as of meat (between -1.79 and -2.56 g/d per year). The healthier food choices and the ability to change food habits could be related to the relatively high health-awareness of the GISELA subjects compared to the federal average of equivalent age groups.

Longitudinal changes in energy expenditure in an elderly German population: a 12-year follow-up

Background/Objectives:This study investigates age-dependent changes in different components of energy expenditure (EE) within the longitudinal study on nutrition and health status in an aging population in Giessen, Germany (GISELA).Subjects/Methods:Between 1994 and 2006, data obtained at a total of 3033 visits from 363 women and 153 men with a mean initial age of 67.4±5.9 and 66.9±5.2 years, respectively, were evaluated. The mean duration of follow-up was 8 years. Resting metabolic rate (RMR) was assessed by indirect calorimetry and physical activity patterns were assessed by questionnaire. EE of physical activity and total EE (TEE) were calculated using multipliers for RMR. Energy intake was determined through a validated 3-day estimated dietary record. Linear mixed models were used to analyze the influence of age on EE adjusted for covariates.Results:Resting metabolic rate decreased in women and men by 158 and 326 kJ/d per decade, respectively; after considering changes in body composition and fat distribution, respective decreases were 81 and 286 kJ/d per decade. EE of physical activity decreased similarly in both sexes (472 kJ/d per decade). TEE dropped in women and men by 540 and 823 kJ/d per decade, respectively. No statistically significant changes in energy intake and body weight were observed in the course of follow-up.Conclusions:The age-dependent decrease in TEE is mainly due to a decrease in physical activity. The stable energy intake and body weight of the GISELA subjects may be indicators for a relatively good health status.

Intake of Vitamin and Mineral Supplements in an Elderly German Population

Aim: To assess the prevalence of vitamin and mineral supplement use in a free-living elderly population and the contribution of these supplements to usual dietary intake. Methods: Analyses are based on data obtained from 388 subjects (≧60 years) participating in the longitudinal study on nutrition and health status in an ageing population in Giessen (GISELA), Germany, in 2002. Nutrient intake from food was assessed by means of a 3-day estimated dietary record. Supplement use was recorded over a period of 3 days using a self-administered questionnaire. Results: Nearly half of the study population consumed at least 1 supplement within these 3 days. The use of supplements was more prevalent among women than among men (51.5 vs. 33.9%). On average women consumed 2.03 ± 1.30 products and men 1.65 ± 1.07 products. Magnesium, vitamin C and vitamin E were supplemented most often by men, while women supplemented magnesium, vitamin E and calcium most often. Most of the supplemented nutrients did not distinctly increase the average intake of the respective nutrients from the diet in this population. However, supplement use markedly decreased the proportions of elderly subjects with an intake below the current reference values for certain nutrients, particularly for vitamin E. Conclusion: Results indicate that the intake of supplements is a common behavior in the population under investigation and therefore has to be considered when nutrient intake is evaluated.

Grade of adiposity affects the impact of fat mass on resting energy expenditure in women.

Body fat mass (FM) adds to the variance in resting energy expenditure (REE). However, the nature and extent of this relationship remains unclear. Using a database of 1306 women and a linear regression model, we systematically analysed the contribution of FM to the total variance in REE at different grades of adiposity (ranges of body %FM). After adjusting for age, the relative contribution of FM on REE variance increased from low (<or= 10 %FM) to normal (>10- <or= 30 %FM) and moderately elevated (>30- <or= 40 %FM) grades of adiposity but decreased sharply at high (>40- # 50 %FM) and very high (>50 %FM) grades of adiposity according to the ratio between regression coefficients. These data suggest that the specific metabolic rate of fat tissue is reduced at high adiposity. This should be considered when REE is normalized for FM in obesity.

Complex correlation structure in consumption rates of major food groups: implications for the assessment of radiation exposure

OBJECTIVE An extensive dataset on individual food consumption was analysed in order to study all pairwise correlations between the consumption rates of 11 major food groups. Additionally, the project aimed to examine and quantify the accuracy of a recently proposed estimator of total food consumption to be used for the estimation of radiation exposure by food. Such an inquiry seems justified, because the proposed estimator implicitly presumes an essentially positive correlation structure in food consumption rates. DESIGN Statistical analysis using representative data gathered in Germany in a nation-wide food consumption survey. SETTING Germany. SUBJECTS Individuals aged between 4 and 94 years namely 10,901 males and 12,308 females. RESULTS The consumption rates of 11 major food categories showed several significantly positive, but also a number of significantly negative, correlations. Negative associations between cereal and potato products persisted consistently over all age groups, independent of sex. Other significantly negative correlations were limited to certain age groups. Reflecting these negative correlations, a subsequent analysis of relative ranks of consumption revealed that no person in the sample had the highest consumption rates in all food groups simultaneously. Based on representative samples, overestimations of 34 to 53% were obtained if--as recently suggested in the context of radiation exposure prediction--the 95th percentiles of total food consumption were determined as sums of the corresponding percentiles of the food groups. CONCLUSIONS The complex correlation structure of food group consumption rates, as identified in this study, bears important implications for various health-related issues. Ignoring them could lead to overly conservative estimations of radiation exposure due to food ingestion or to confounding effects in epidemiological studies on nutritional risk factors of diseases. The results also indicate that a distinction into different dietary patterns might be useful in characterising different consumption habits.

Versorgungszustand von Teilnehmern der Gießener Seniorenlangzeitstudie (GISELA) mit antioxidativ wirksamen Vitaminen und Selen

Zusammenfassung Im Rahmen der Gießener Seniorenlangzeitstudie (GISELA) wurden Basiswerte zum Antioxidanzienstatus von 85 Gießener Senioren erhoben, die mindestens 60 Jahre alt sind, sich selbst versorgen, nicht rauchen und keine Vitamin- oder Mineralstoffpräparate einnehmen. Hierzu wurden die Nährstoffzufuhr mittels eines speziell für diese Studie entwickelten und validierten 3-Tage-Schätzprotokolls erfaßt und die Konzentrationen von Vitamin C, Vitamin E, β-Carotin und Selen im Blutplasma der Senioren bestimmt. Die Ergebnisse zeigen, daß die untersuchten Senioren im Mittel durch ihre Ernährung eine gute Versorgung mit den antioxidativ wirksamen Nährstoffen erreichen. Obwohl bei der Nährstoffzufuhr keine Unterschiede zwischen den Geschlechtern festgestellt wurden, wiesen die Frauen im Vergleich zu den Männern bei allen untersuchten Substanzen signifikant höhere Plasmaspiegel auf.Summary Within the longitudinal study on nutrition and health status in an aging population of Giessen, Germany, baseline measurements with regard to antioxidant status were obtained in 85 free living elderly persons. The subjects were at least 60 years old, non-smoking, feeding themselves, and not supplementing any vitamins or minerals. Dietary intake of nutrients was assessed by means of a 3-day estimated food record, which was especially developed and validated for this study. Antioxidant status was evaluated by fasting plasma concentrations of vitamin C, E, β-carotene, and selenium. The results show that in this study group self-determined nutrition provides enough nutrients to yield a good antioxidant status in the advanced age. Although no differences could be detected in dietary intake of vitamin C, E, and β-carotene between males and females, significantly higher plasma concentrations of all substances investigated were found in females when compared to males.