Britta Hitze

Influence of Partial Sleep Deprivation on Energy Balance and Insulin Sensitivity in Healthy Women

Background: Voluntary sleep restriction is a lifestyle feature of modern societies that may contribute to obesity and diabetes. The aim of the study was to investigate the impact of partial sleep deprivation on the regulation of energy balance and insulin sensitivity. Subjects and Methods: In a controlled intervention, 14 healthy women (age 23–38 years, BMI 20.0–36.6 kg/m2) were investigated after 2 nights of >8 h sleep/night (T0), after 4 nights of consecutively increasing sleep curtailment (7 h sleep/ night, 6 h sleep/night, 6 h sleep/night and 4 h sleep/night; T1) and after 2 nights of sleep recovery (>8 h sleep/night; T2). Resting and total energy expenditure (REE, TEE), glucose-induced thermogenesis (GIT), physical activity, energy intake, glucose tolerance and endocrine parameters were assessed. Results: After a decrease in sleep du-ration, energy intake (+20%), body weight (+0.4 kg), leptin / fat mass (+29%), free triiodothyronine (+19%), free thyroxine (+10%) and GIT (+34%) significantly increased (all p < 0.05). Mean REE, physical activity, TEE, oral glucose tolerance, and ghrelin levels remained unchanged at T1. The effect of sleep loss on GIT, fT3 and fT4 levels was inversely related to fat mass. Conclusion: Short-term sleep deprivation increased energy intake and led to a net weight gain in women. The effect of sleep restriction on energy expenditure needs to be specifically addressed in future studies using reference methods for total energy expenditure.

Determinants and impact of sleep duration in children and adolescents: data of the Kiel Obesity Prevention Study.

Background/Objectives: This study investigates determinants of sleep duration and its impact on nutritional status, resting energy expenditure (REE), cardiometabolic risk factors and hormones in children/adolescents.Subjects/Methods: In 207 girls and 207 boys (13.0±3.4 (6.1–19.9) years) body mass index standard deviation score (BMI SDS), waist circumference (WC) z-score, body composition (air-displacement plethysmography), REE (ventilated hood system; n=312) and cardiometabolic risk factors/hormones (n=250) were assessed. Greater than 90th percentile of BMI/WC references was defined as overweight/overwaist. Sleep duration, media consumption (TV watching/computer use), physical activity, dietary habits, parental BMI, socio-economic status and early infancy were assessed by questionnaire. Short sleep was defined as <10 h per day for children <10 years and otherwise <9 h per day.Results: Total 15.9% participants were overweight, mean sleep duration was 8.9±1.3 h per day. Age explained most variance in sleep (girls: 57.0%; boys: 41.2%) besides a high nutrition quality score (girls: 0.9%) and a low media consumption (boys: 1.3%). Sleep was inversely associated with BMI SDS/WC z-score (girls: r=−0.17/−0.19, P<0.05; boys: r=−0.21/−0.20, P<0.01), which was strengthened after adjusting for confounders. Short vs long sleep was associated with 5.5-/2.3-fold higher risks for obesity/overwaist (girls). After adjusting for age, REE (adjusted for fat-free mass) was positively associated with sleep in boys (r=0.16, P<0.05). Independently of age and WC z-score, short sleep was associated with lower adiponectin levels in boys (11.7 vs 14.4 μg/ml, P<0.05); leptin levels were inversely related to sleep in girls (r=−0.23, P<0.05). Homoeostasis model assessment–insulin resistance (r=−0.20, P<0.05) and insulin levels (r=−0.20, P<0.05) were associated with sleep (girls), which depended on WC z-score.Conclusions: Age mostly determined sleep. Short sleep was related to a higher BMI SDS/WC z-score (girls/boys), a lower REE (boys), higher leptin (girls) and lower adiponectin levels (boys).

Contribution of individual organ mass loss to weight loss–associated decline in resting energy expenditure

BACKGROUND Weight loss leads to reduced resting energy expenditure (REE) independent of fat-free mass (FFM) and fat mass (FM) loss, but the effect of changes in FFM composition is unclear. OBJECTIVE We hypothesized that a decrease in REE adjusted for FFM with weight loss would be partly explained by a disproportionate loss in the high metabolic activity component of FFM. DESIGN Forty-five overweight and obese women [body mass index (in kg/m(2)): 28.7-46.8] aged 22-46 y followed a low-calorie diet for 12.7 +/- 2.2 wk. Body composition was measured by magnetic resonance imaging, dual-energy X-ray absorptiometry, and a 4-compartment model. REE measured by indirect calorimetry (REEm) was compared with REE calculated from detailed body-composition analysis (REEc) by using specific organ metabolic rates (ie, organ REE/mass). RESULTS Weight loss was 9.5 +/- 3.4 kg (8.0 +/- 2.9 kg FM and 1.5 +/- 3.1 kg FFM). Decreases in REE (-8%), free triiodothyronine concentrations (-8%), muscle (-3%), heart (-5%), liver (-4%), and kidney mass (-6%) were observed (all P < 0.05). Relative loss in organ mass was significantly higher (P < 0.01) than was the change in low metabolically active FFM components (muscle, bone, and residual mass). After weight loss, REEm - REEc decreased from 0.24 +/- 0.58 to 0.01 +/- 0.44 MJ/d (P = 0.01) and correlated with the decrease in free triiodothyronine concentrations (r = 0.33, P < 0.05). Women with high adaptive thermogenesis (defined as REEm - REEc < -0.17 MJ/d) had less weight loss and conserved FFM, liver, and kidney mass. CONCLUSIONS After weight loss, almost 50% of the decrease in REEm was explained by losses in FFM and FM. The variability in REEm explained by body composition increased to 60% by also considering the weight of individual organs.

Measurement of Waist Circumference at Four Different Sites in Children, Adolescents, and Young Adults: Concordance and Correlation with Nutritional Status as well as Cardiometabolic Risk Factors

Background: This study investigates the concordance of four waist circumference (WC) measurement sites, and examines their relationships with nutritional status and cardiometabolic risk. Subjects and Methods: In 91 females / 89 males (6.1–19.9 years; 12.2% overweight), WC was assessed beneath the lowest rib (WCR), 4 cm above the umbilicus (WC4), above the iliac crest (WCC), and midway between WCR/WCC (WCM). ‘Overwaist’ was defined as a WC > 90th age-/sex-specific percentile. Pubertal stage was assessed according to Tanner. Body composition (air-displacement plethysmography), blood pressure, lipid profile, glucose/insulin levels, and HOMA-IR (homeostasis model assessment of insulin resistance) were measured. Results: Medians of WCs (cm) for females/males were WCR (64.4/69.5) < WC4 (64.6/70.2) < WCM (67.1/71.2) < WCC (71.5/ 74.2). Although closely related to each other (all r > 0.93; p < 0.001), paired comparisons revealed differences between WCs in their magnitudes which was stronger for females than males. Prevalence of ‘overwaist’ differed according to measurement site in females/males: WCR (13.2/15.7%) < WC4 (14.3/ 19.1%) < WCM (18.7/22.5%) < WCC (37.4/30.3%). After adjusting for age and pubertal status, WCs were closely related to body mass index (BMI) (all r > 0.86; p < 0.001), percent fat mass (%FM; all r > 0.61; p < 0.001), and comparably associated with cardiometabolic risk factors. However, stronger correlations were found for i) WCR vs. WC4 with BMI in males (r = 0.93 vs. 0.91; p < 0.05), ii) WCC vs. WC4 with %FM in females (r = 0.67 vs. 0.61; p < 0.05), iii) WCC vs. WCR with triglycerides in females (r = 0.29 vs. r = 0.22; p < 0.05), and iv) WCC (r = 0.36) vs. other WCs (r = 0.30–0.32) with low-density lipoprotein cholesterol (LDL-C) in males (p < 0.05). Conclusion: WCs measured at different sites were closely correlated with BMI and %FM as well as comparably associated with cardiometabolic risk factors. However, different WCs had different magnitudes, which was more obvious in females and led to discordant results with respect to ‘overwaist’ and risk assessment.

Long‐term effects of rapid weight gain in children, adolescents and young adults with appropriate birth weight for gestational age: the kiel obesity prevention study

Aim:  This study investigates the effect of rapid weight gain in term children, adolescents and young adults born appropriate for gestational age.

Postprandial triglyceride response in men: role of overweight, abdominal fat and nutrition.

Objective: The study analyses i) the effect of overweight, waist circumference and dietary habits on postprandial (pp) triglyceride (TG) response and compares ii) pp TG response with fasting TG levels and iii) pp TG peak values with TG-AUC (area under curve) with respect to cardiometabolic risk assessment. Methods: In 100 men (44–68 years) body composition (air-displacement plethysmography), dietary habits, cardiometabolic risk and pp lipid metabolism (standardised lipid load) were assessed. A pp TG peak value of 260 mg/dl was used as a cut-off to classify TG normal- and high-responders. Results: pp TG response had positive associations with BMI (r = 0.24; p < 0.05), fat mass (r = 0.28; p < 0.01), waist circumference (r = 0.33; p < 0.01), systolic blood pressure (r = 0.21; p < 0.05), fasting (r = 0.29; p < 0.01) and pp glucose (r = 0.40; p < 0.001), fasting (r = 0.38; p < 0.001) and pp insulin levels (r = 0.46; p < 0.001), and inverse associations with HDL-C (r = –0.43; p < 0.001) and intake of dietary fibre (r = –0.31; p < 0.05). Fasting TG levels had a greater contribution to the variance in 12 of 14 cardiometabolic risk factors compared to pp TG response. TG-AUC was highly correlated to cardiometabolic risk. Conclusion: Overweight, abdominal fat and a low intake of dietary fibre were determinants of increased pp TG response. Contrary to findings in younger normal-weight men, fasting TG levels had a stronger association with cardio metabolic risk compared to pp TG response. This might be explained by differences in fat mass.

Low plasma lactate concentration as a biomarker of an incompetent brain-pull: A risk factor for weight gain in type 2 diabetes patients

OBJECTIVE Body weight development is closely regulated by central nervous mechanisms. As has been demonstrated recently, the capability of the brain to actively demand energy from the body (brain-pull) is indispensable for the maintenance of systemic homeostasis. A deficit in this brain-pull may result in compensatory ingestive behavior followed by weight gain in the medium or long term. The aim of this study was to establish a biomarker of such an incompetent brain-pull. Since lactate is an alternative cerebral energy substrate to glucose, we investigated whether low fasting plasma lactate concentrations are associated with weight gain and increased feelings of hunger in patients with type 2 diabetes over a 3-year period. METHODS In a population based cohort study 134 type 2 diabetes patients were examined at baseline and 3-year follow-up. Plasma lactate concentrations and additional hormones associated with food intake such as e.g. insulin, or leptin, as well as psychological variables like hunger feelings before and after a standardized breakfast were measured. The relation between fasting plasma lactate concentrations and postprandial hunger as well as follow-up weight was analyzed. RESULTS Low fasting plasma lactate concentrations predicted a higher 3-year follow-up weight (B=-1.268, SE=0.625, p=0.04). Moreover, low fasting plasma lactate concentrations were associated with more pronounced feelings of postprandial hunger (B=-0.406, SE=0.137, p<0.01). CONCLUSIONS We conclude that low plasma lactate concentrations may represent a biomarker of an incompetent brain-pull, which is associated with weight gain and increased postprandial hunger in patients with type 2 diabetes mellitus. These results are in line with the view that plasma lactate can be used by the brain as an alternative energy substrate and thereby to some extent prevent overeating and obesity.

Acknowledgement to Revierwers

Accessible online at: www.karger.com/ofa Fax +49 761 4 52 07 14 Information@Karger.de www.karger.com Johannes Klein, Lübeck Antje Körner, Leipzig Peter Kovacs, Leipzig Kathrin Kromeyer-Hausschild, Jena Detlef Kunze, Munich Monika Lechleitner, Zirl Tanja Legenbauer, Dortmund Beat Lutz, Mainz Robert G. MacKenzie, Canfield Detroit, MI Amelia Marti del Moral, Pamplona David Meyre, Lille Dragan Micic, Belgrade Susanne Moebus, Essen Dénes Molnár, Pécs Manfred J. Müller, Kiel Timo Müller, Essen Falk Müller-Riemenschneider, Berlin Simone Munsch, Basel Susanne Neschen, Neuherberg Monika Neuhäuser-Berthold, Gießen Enzo Nisoli, Milan Rubén Nogueiras, Santiago de Compostela Inger Öhlund, Umeå Lucia Pacifico, Rome Dorit Packert Zobel, Gentofte Ursula Pauli-Pott, Gießen Andreas F.H. Pfeiffer, Nuthetal Paul T. Pfluger, Cincinnati, OH Antonio Piccoli, Padova Kirsi Pietilainen, Helsinki Angelo Pietrobelli, Verona Sandra Plachta-Danielzik, Kiel Ursula Plöckinger, Berlin Michael Ristow, Jena Stephan Rössner, Stockholm Jürgen Schäfer, Marburg André Scherag, Essen Torsten Schöneberg, Leipzig Ulrich Schweiger, Lübeck Anders Sjödin, Frederiksberg Thomas Skurk, Freising-Weihenstephan Joachim Spranger, Berlin Rick Stein, St. Louis, MO Susanne Tan, Essen Ya-Xiong Tao, Auburn, AL Jenny Tong, Cincinnati, OH Anke Tönjes, Leipzig Hermann Toplak, Graz Michael Toschke, London Angelo Tremblay, Quebec, QC Otto Tschritter, Tübingen Constantine Tsigos, Athens Andreas van Egmond-Fröhlich, Berchtesgarden Silja Vocks, Bochum Henry Völzke, Greifswald Martin Wabitsch, Ulm Petra Warschburger, Potsdam Kelly H. Webber, Lexington, KY Ram Weiss, Jerusalem Joachim Westenhöfer, Hamburg Klaas R. Westerterp, Maastricht Stephen Whybrow, Bucksburn, Aberdeen Petra Wiedmer, Nuthetal Silke Wolfenstetter, Neuherberg Andreas Ziegler, Lübeck Stephan Zipfel, Tübingen Zane Andrews, Clayton Victoria Ion Anghelescu, Berlin Sandor Batkai, Bethesda, MD Martin Bidlingmaier, Munich Matthias Blüher, Leipzig Yvonne Böttcher, Leipzig Michael Bowling, Chapel Hill, NC Georg Brabant, Manchester Tamara Castaneda, Toledo, OH Barbara Cresci, Florence Lilian de Jonge, Baton Rouge, LA Martina de Zwaan, Erlangen Vincenzo Di Francesco, Verona Manuela Dittmar, Kiel Stefan Engeli, Hanover Mathias Faßhauer, Leipzig Pamela Fischer-Posovszky, Ulm David Frankenfield, Hershey Brigitte Ganter, Redwood City, CA Lien Goossens, Gent Christine Graf, Köln Sarah Haas Lockie, Cincinnati, OH Andreas Hamann, Bad Nauheim Johannes Hebebrand, Essen Stephan Herpertz, Dortmund Anja Hilbert, Marburg Barbara Hoffmann, Essen Susanna Hofmann, Cincinnati, OH Betina Højgaard, Copenhagen Geng-Ye Ji, Beijing Jose Jiminez, Boston, MS Laura Johnson, Cambridge Alex Johnstone, Bucksburn Aberdeen Masa Kagawa, Kelvin Grove Kaisu Keskitalo, Helsinki Acknowledgement to Reviewers

Meetings and Conferences

6-8 December 2007. International Conference on Social Statistics and Ethnic Diversity: Should We Count, How Should We Count and Why?, Montréal, Canada. Contact: Amélie Gagnon, Coordinator. Email: a.gagnon@umontreal.ca or consult the conference’s (www.ciqss.umontreal.ca/en/ ssed), the QICSS’ (www.ciqss.umontreal.ca) or the INED’s (www.ined.fr) websites; URL: Website: http://www.ciqss.umontreal.ca/en/SSED/index.html