Glucose tolerance in a Saharan nomad population--the Broayas, from the Toubou ethnic group

Oral plucose tolerance was studied in the Toubou Broayas living in northeaster Niger. Mean fasting plasma level of glucose was 64 +/- 22 (S.D.) mg./100 ml. Two hours after oral administration of 100 gm. glucose, the level was 74 +/- 26 mg./100 ml. Plasma insulin levels were, respectively, 18 +/- 13 and 36 +/- 24 muU./ml. There was no sex difference. Older subjects had higher glucose levels and heavier females had higher insulin levels two hours after glucose administration. In six subjects (4 per cent) the plasma glucose level exceeded either 110 or 130 mg./100 ml. in the fasting state or after glucose administration, respectively, without, however, exceeding 150 mg./100 ml. in any of them. The low prevalence of glucose intolerance in this population is discussed with regard to their nutritional conditions (80 per cent carbohydrates) and their physical activity (nomadism). The Broaya group, in whom obesity is unknown, appears to be well adapted to its extreme environment.