Julia H Goedecke1, Cindy George2, Katherine Veras3, Nasheeta Peer4, Carl Lombard5, Hendriena Victor6, Krisela Steyn7, Naomi S Levitt7. 1. Non-Communicable Disease Research Unit, South African Medical Research Council, Francie van Zijl Drive, Parow Valley, 7505 Cape Town, South Africa; Division of Exercise Science and Sports Medicine, Department of Human Biology, 3rd Floor Sports Science Institute of South Africa, Boundary Road, Newlands 7700, South Africa. Electronic address: julia.goedecke@mrc.ac.za. 2. Non-Communicable Disease Research Unit, South African Medical Research Council, Francie van Zijl Drive, Parow Valley, 7505 Cape Town, South Africa. 3. Division of Exercise Science and Sports Medicine, Department of Human Biology, 3rd Floor Sports Science Institute of South Africa, Boundary Road, Newlands 7700, South Africa; Department of Physiology and Biophysics, University of São Paulo, São Paulo, Brazil. 4. Non-Communicable Disease Research Unit, South African Medical Research Council, Francie van Zijl Drive, Parow Valley, 7505 Cape Town, South Africa; Division of Diabetes and Endocrinology, Department of Medicine, University of Cape Town, South Africa. 5. Biostatistics Unit, South African Medical Research Council, Francie van Zijl Drive, Parow Valley, 7505 Cape Town, South Africa. 6. Division of Exercise Science and Sports Medicine, Department of Human Biology, 3rd Floor Sports Science Institute of South Africa, Boundary Road, Newlands 7700, South Africa. 7. Division of Diabetes and Endocrinology, Department of Medicine, University of Cape Town, South Africa.
Abstract
AIMS: Black Africans are disproportionally affected by type 2 diabetes, but the pathophysiology is poorly understood. The study aimed to examine the effect of sex and age on insulin sensitivity and insulin response in black South African adults. METHODS: This cross-sectional study included a random sample of 179 men and 260 women aged 25-74years with normal glucose tolerance from 5 peri-urban townships in Cape Town, SA. Insulin sensitivity (insulin sensitivity index, ISI0,120) and response (insulinogenic index, IGI), and the disposition index (DI, ISI0,120×IGI), derived from an oral glucose tolerance test, were measured. RESULTS: Although men were older (median [interquartile range]: 39 [30-48] vs. 35 [29-44], P=0.021) and had significantly lower BMI than women (22.6 [20.0-25.3] vs. 31.0 [25.9-35.7] kg/m2, P=0.001), DI was not different (P=0.740), but ISI0,120 was higher (P=0.007) and IGI was lower (P=0.074) in men than women, adjusting for age and BMI. With increasing age, DI (β (95%CI): -24.4 (-36.3 to -12.5), P<0.001) and IGI (β (95%CI): -4.9 (-7.5 to -2.2), P<0.001) decreased similarly in both sexes, but ISI0,120 did not change (β (95%CI): 0.005 (-0.20 to 0.03), P=0.675). CONCLUSION: Black South African women with normal glucose tolerance have lower insulin sensitivity than their male counterparts, but increase their insulin response to maintain normoglycemia. With increasing age, insulin sensitivity remains unchanged, but the insulin response decreases at a similar rate in men and women.
AIMS: Black Africans are disproportionally affected by type 2 diabetes, but the pathophysiology is poorly understood. The study aimed to examine the effect of sex and age on insulin sensitivity and insulin response in black South African adults. METHODS: This cross-sectional study included a random sample of 179 men and 260 women aged 25-74years with normal glucose tolerance from 5 peri-urban townships in Cape Town, SA. Insulin sensitivity (insulin sensitivity index, ISI0,120) and response (insulinogenic index, IGI), and the disposition index (DI, ISI0,120×IGI), derived from an oral glucose tolerance test, were measured. RESULTS: Although men were older (median [interquartile range]: 39 [30-48] vs. 35 [29-44], P=0.021) and had significantly lower BMI than women (22.6 [20.0-25.3] vs. 31.0 [25.9-35.7] kg/m2, P=0.001), DI was not different (P=0.740), but ISI0,120 was higher (P=0.007) and IGI was lower (P=0.074) in men than women, adjusting for age and BMI. With increasing age, DI (β (95%CI): -24.4 (-36.3 to -12.5), P<0.001) and IGI (β (95%CI): -4.9 (-7.5 to -2.2), P<0.001) decreased similarly in both sexes, but ISI0,120 did not change (β (95%CI): 0.005 (-0.20 to 0.03), P=0.675). CONCLUSION: Black South African women with normal glucose tolerance have lower insulin sensitivity than their male counterparts, but increase their insulin response to maintain normoglycemia. With increasing age, insulin sensitivity remains unchanged, but the insulin response decreases at a similar rate in men and women.
Authors: Michael J A Reid; Yifei Ma; Iya Golovaty; Samson Okello; Ruth Sentongo; Maggie Feng; Alexander C Tsai; Bernard Kakuhikire; Russell Tracy; Peter W Hunt; Mark Siedner; Phyllis C Tien Journal: AIDS Patient Care STDS Date: 2019-06-12 Impact factor: 5.078
Authors: Amy E Mendham; Lisa K Micklesfield; Fredrik Karpe; Andre Pascal Kengne; Tinashe Chikowore; Clement N Kufe; Maphoko Masemola; Nigel J Crowther; Shane A Norris; Tommy Olsson; Sölve Elmståhl; Tove Fall; Lars Lind; Julia H Goedecke Journal: Diabetologia Date: 2022-09-17 Impact factor: 10.460
Authors: Julia H Goedecke; Amy E Mendham; Louise Clamp; Pamela A Nono Nankam; Melony C Fortuin-de Smidt; Lindokuhle Phiri; Lisa K Micklesfield; Dheshnie Keswell; Nicholas J Woudberg; Sandrine Lecour; Ali Alhamud; Mamadou Kaba; Faith M Lutomia; Paul J van Jaarsveld; Anniza de Villiers; Steven E Kahn; Elin Chorell; Jon Hauksson; Tommy Olsson Journal: JMIR Res Protoc Date: 2018-04-18
Authors: Oluwatoyosi Bello; Cynthia Mohandas; Fariba Shojee-Moradie; Nicola Jackson; Olah Hakim; K George M M Alberti; Janet L Peacock; A Margot Umpleby; Stephanie A Amiel; Louise M Goff Journal: Diabetologia Date: 2019-02-06 Impact factor: 10.122
Authors: Carmen Pheiffer; Victoria Pillay-van Wyk; Eunice Turawa; Naomi Levitt; Andre P Kengne; Debbie Bradshaw Journal: Int J Environ Res Public Health Date: 2021-05-30 Impact factor: 3.390