Dale E Rae1, Paula R Pienaar2, Rob H P Henst2, Laura C Roden3, Julia H Goedecke4. 1. Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. Electronic address: Dale.Rae@uct.ac.za. 2. Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. 3. Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa. 4. Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Non-communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.
Abstract
OBJECTIVES: South African women have disproportionately high levels of overweight and obesity, and ethnic differences in obesity and insulin resistance have been observed. We investigated associations between self-reported sleep duration, obesity and insulin resistance in Black and White South African women. DESIGN: Cross-sectional. PARTICIPANTS: Black normal-weight (n = 122), Black obese (n = 133), White normal-weight (n = 87) and White obese (n = 63) urban South African women, aged 18 to 45y. MEASUREMENTS: Participants completed questionnaires capturing self-reported sleep duration, demographic, socioeconomic, medical history and lifestyle information. Body composition and fasting blood glucose and insulin concentrations were measured. RESULTS: The Black women reported longer sleep than the White women (median: 8 h, interquartile range: 8-10 h v 7(7-8) respectively, P < .001). Adjusted models indicated that women sleeping <7 h sleep were less likely to be obese (P = .035) or insulin resistant (P = .032), while those sleeping >9 h were more likely to be insulin resistant (P = .014) than those sleeping 7 to 9 h. Shorter self-reported sleep was associated with less insulin resistance (<7 h v 7-9 h: P = .018) and longer sleep with more insulin resistance (>9 h v 7-9 h: P = .047) in the Black but not White women. CONCLUSIONS: Future research that objectively measures sleep duration is needed to confirm these observations and investigate potential factors contributing to the relationship between sleep and risk for non-communicable diseases in different ethnic groups.
OBJECTIVES: South African women have disproportionately high levels of overweight and obesity, and ethnic differences in obesity and insulin resistance have been observed. We investigated associations between self-reported sleep duration, obesity and insulin resistance in Black and White South African women. DESIGN: Cross-sectional. PARTICIPANTS: Black normal-weight (n = 122), Black obese (n = 133), White normal-weight (n = 87) and White obese (n = 63) urban South African women, aged 18 to 45y. MEASUREMENTS: Participants completed questionnaires capturing self-reported sleep duration, demographic, socioeconomic, medical history and lifestyle information. Body composition and fasting blood glucose and insulin concentrations were measured. RESULTS: The Black women reported longer sleep than the White women (median: 8 h, interquartile range: 8-10 h v 7(7-8) respectively, P < .001). Adjusted models indicated that women sleeping <7 h sleep were less likely to be obese (P = .035) or insulin resistant (P = .032), while those sleeping >9 h were more likely to be insulin resistant (P = .014) than those sleeping 7 to 9 h. Shorter self-reported sleep was associated with less insulin resistance (<7 h v 7-9 h: P = .018) and longer sleep with more insulin resistance (>9 h v 7-9 h: P = .047) in the Black but not White women. CONCLUSIONS: Future research that objectively measures sleep duration is needed to confirm these observations and investigate potential factors contributing to the relationship between sleep and risk for non-communicable diseases in different ethnic groups.
Authors: Dale Elizabeth Rae; Lara Ruth Dugas; Laura Catherine Roden; Estelle Vicki Lambert; Pascal Bovet; Jacob Plange-Rhule; Terrence Forrester; Walter Riesen; Wolfgang Korte; Stephanie J Crowley; Sirimon Reutrakul; Amy Luke Journal: Sleep Health Date: 2020-04-19
Authors: Ilaria Pina; Amy E Mendham; Simone A Tomaz; Julia H Goedecke; Lisa K Micklesfield; Naomi E Brooks; Iain J Gallagher; Rachel Crockett; Paul Dudchenko; Angus M Hunter Journal: Int J Environ Res Public Health Date: 2021-04-19 Impact factor: 3.390
Authors: Lisa K Micklesfield; Kate Westgate; Antonia Smith; Clement N Kufe; Amy E Mendham; Tim Lindsay; Katrien Wijndaele; Julia H Goedecke; Soren Brage Journal: Med Sci Sports Exerc Date: 2022-04-22