Circadian variations of blood sugar and plasma insulin levels in man

Sex related diurnal variations in venous blood glucose and plasma insulin levels effects of estrogens in men

“…In the studies using meals by Malherbe et al [3] and by Rigas et al [4] prior fasting time between morning and midday was identical to that of our study and these studies were subject to the same criticism. But in the work of Barter et al [5] identical fasting periods between meals were designed and lower insulin secretion was observed in men in the afternoon than in the morning.…”

“…The insulin secretion induced by oral glucose [1,6,7, 11,13], tolbutamide [2,13] or isoealorie meals [3,5] was more pronounced in the morning than in the afternoon. Blood glucose levels were lower in the morning than in the afternoon in response to various stimuli [1, 2, 6, 7, 9--13], but not after meals [3].After 3 and 4 days of total fast, plasma insulin levels were higher in the morning than in the afternoon in normal young men [1r These studies were done mainly or only in men.In male rats a daily rhythm of plasma glucose and insulin levels [15] and a diurnal cycle in the pancreatic beta and alpha 2 cells nuclear size [16] were described.The possibility that the circadian variations observed in blood glucose and plasma insulin levels might be sex-related has not been studied until now. However sex-related differences have been observed in substrate and hormone studies.…”

“…The insulin secretion induced by oral glucose [1,6,7, 11,13], tolbutamide [2,13] or isoealorie meals [3,5] was more pronounced in the morning than in the afternoon. Blood glucose levels were lower in the morning than in the afternoon in response to various stimuli [1, 2, 6, 7, 9--13], but not after meals [3].…”

“…Blood glucose levels were lower in the morning than in the afternoon in response to various stimuli [1, 2, 6, 7, 9--13], but not after meals [3].…”

Neuroendocrinology of hyperphagias and obesities

“…Also, continuous metabolic expenditure and oxygen supply are associated with discontinuous energy supply in the form of meals. A study of the feeding pattern of many species has shown a dual periodicity (Duncan et al, 1970 ;Le Magnen and Tallon, 1966 ;Natelson and Bonbright, 1978 ;Sanderson and VanderVl!eele, 1975 ;Wolf and Hainsworth, 1977 (Aparicio et al, 1974 ;Carroll and Nestel, 1973 ;Gibson and Jarrett, 1972 ;Malherbe et al, 1969 ;Schlierf and Dorow, 1973 ;Sensi and Capani, 1976) Brobeck, 1952 ;Grossman et al, 1978 ;Stricker, Swerdloff and Zigmond, 1978) and definitively prevents glucopeniciinduced food intake when insulin or 2-deoxy-D-glucose (2 DG) is intravenously infused (Epstein and Teitelbaum, 1967 ;Nicolaidis and Meile, 1972).…”