Effects of size, time of day and sequence of meal ingestion on carbohydrate tolerance in normal subjects

Hall, Larry D.; Westland, R.; O’Brien, Peter C.; Go, Vay Liang W.; Haymond, Morey W.; Rizza, Robert A.

doi:10.1007/bf00253193

Cited by 92 publications

(56 citation statements)

References 45 publications

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“…This suggests that a highcarbohydrate pre-meal eliminates the effect of the diurnal rhythm of glucose tolerance. It has been reported previously that both postprandial glucose and lipid tolerance can be influenced by the nutrient composition of the previous meal (Service et al 1983, Frape et al 1997. One factor in need of consideration is the time elapsed since the previous sleep, which was considerably greater on the test meal study day immediately after the phase shift than either of the other two.…”

Section: Discussionmentioning

confidence: 99%

Altered postprandial hormone and metabolic responses in a simulated shift work environment

Ribeiro¹,

Hampton²,

Morgan³

et al. 1998

Journal of Endocrinology

137

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The circadian rhythms of most night shift workers do not adapt fully to the imposed behavioural schedule, and this factor is considered to be responsible for many of the reported health problems. One way in which such disturbances might be mediated is through inappropriate hormonal and metabolic responses to meals, on the night shift.Twelve healthy subjects (four males and eight females) were studied on three occasions at the same clock time (1330 h), but at different body clock times, after consuming test meals, first in their normal environment, secondly after a forced 9 h phase advance (body clock time approximately 2230 h) and then again 2 days later in the normal environment. They were given a low-fat pre-meal at 0800 h, then a test meal at 1330 h with blood sampling for the following 9 h. Parameters measured included plasma glucose, non-esterified fatty acids (NEFAs), triacylglycerol (TAG), insulin, C-peptide, proinsulin and glucosedependent insulinotropic polypeptide, and urinary 6-sulphatoxymelatonin.In contrast with a previous study with a high-fat premeal, postprandial glucose and insulin responses were not affected by the phase shift. However, basal plasma NEFAs were lower immediately after the phase shift (P<0·05). Incremental (difference from basal) TAG responses were significantly higher (P<0·05) immediately after the phase shift compared with before. Two-day post-phase shift responses showed partial reversion to baseline values.This study suggests that it takes at least 2 days to adapt to eating meals on a simulated night shift, and that the nutritional content of the pre-meals consumed can have a marked effect on postprandial responses during a simulated phase shift. Such findings may provide a partial explanation for the increased occurrence of cardiovascular disease reported in shift workers.

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Section: Discussionmentioning

confidence: 99%

Altered postprandial hormone and metabolic responses in a simulated shift work environment

Ribeiro¹,

Hampton²,

Morgan³

et al. 1998

Journal of Endocrinology

137

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“…Studies have been carried out to investigate postprandial plasma glucose levels following bolus doses of glucose at different times of the day (Service et al 1983). The persistence of the diurnal variation of glucose tolerance under conditions devoid of zeitgebers (the environmental factors that entrain or synchronise a rhythm) strongly suggests that the normal pattern of glucose tolerance, through a given 24 h period, must at least be partially controlled by signals originating from the body clock (Van Cauter et al 1989).…”

Section: Introductionmentioning

confidence: 99%

Postprandial hormone and metabolic responses amongst shift workers in Antarctica

Lund¹,

Arendt²,

Hampton³

et al. 2001

Journal of Endocrinology

179

120

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The circadian rhythms of many night-shift workers are maladapted to their imposed behavioural schedule, and this factor may be implicated in the increased occurrence of cardiovascular disease (CVD) reported in shift workers. One way in which CVD risk could be mediated is through inappropriate hormonal and metabolic responses to meals. This study investigated the responses to standard meals at different circadian times in a group of night-shift workers on a British Antarctic Survey station at Halley Bay (75 S) in Antarctica.Twelve healthy subjects (ten men and two women) were recruited. Their postprandial hormone and metabolic responses to an identical mixed test meal of 3330 kJ were measured on three occasions: (i) during daytime on a normal working day, (ii) during night-time at the beginning of a period of night-shift work, and (iii) during the daytime on return from nightworking to daytime working. Venous blood was taken for 9 h after the meal for the measurement of glucose, insulin, triacylglycerol (TAG) and non-esterified fatty acids. Urine was collected 4-hourly (longer during sleep) on each test day for assessment of the circadian phase via 6-sulphatoxymelatonin (aMT6s) assay.During normal daytime working, aMT6s acrophase was delayed (7·7 1·0 h (...)) compared with that previously found in temperate zones in a comparable age-group. During the night shift a further delay was evident (11·8 1·9 h) and subjects' acrophases remained delayed 2 days after return to daytime working (12·4 1·8 h). Integrated postprandial glucose, insulin and TAG responses were significantly elevated during the night shift compared with normal daytime working. Two days after their return to daytime working, subjects' postprandial glucose and insulin responses had returned to pre-shift levels; however, integrated TAG levels remained significantly elevated.These results are very similar to those previously found in simulated night-shift conditions; it is the first time such changes have been reported in real shift workers in field conditions. They provide evidence that the abnormal metabolic responses to meals taken at night during unadapted night shifts are due, at least in part, to a relative insulin resistance, which could contribute to the documented cardiovascular morbidity associated with shift work. When applied to the 20% of the UK workforce currently employed on shift work, these findings have major significance from an occupational health perspective.

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“…circadian disruption | shift work | night work | glucose metabolism | diabetes I n healthy humans, there is a strong time-of-day variation in glucose tolerance, with a peak in the morning and a trough in the evening and night (1)(2)(3)(4)(5)(6). Understanding the underlying mechanisms of the day/night variation in glucose tolerance is important for diurnally active individuals as well as shift workers, who are at increased risk for developing type 2 diabetes (7-9).…”

mentioning

confidence: 99%

Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans

Morris

Yang

Garcia

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

344

336

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Glucose tolerance is lower in the evening and at night than in the morning. However, the relative contribution of the circadian system vs. the behavioral cycle (including the sleep/wake and fasting/ feeding cycles) is unclear. Furthermore, although shift work is a diabetes risk factor, the separate impact on glucose tolerance of the behavioral cycle, circadian phase, and circadian disruption (i.e., misalignment between the central circadian pacemaker and the behavioral cycle) has not been systematically studied. Here we show-by using two 8-d laboratory protocols-in healthy adults that the circadian system and circadian misalignment have distinct influences on glucose tolerance, both separate from the behavioral cycle. First, postprandial glucose was 17% higher (i.e., lower glucose tolerance) in the biological evening (8:00 PM) than morning (8:00 AM; i.e., a circadian phase effect), independent of the behavioral cycle effect. Second, circadian misalignment itself (12-h behavioral cycle inversion) increased postprandial glucose by 6%. Third, these variations in glucose tolerance appeared to be explained, at least in part, by different mechanisms: during the biological evening by decreased pancreatic β-cell function (27% lower earlyphase insulin) and during circadian misalignment presumably by decreased insulin sensitivity (elevated postprandial glucose despite 14% higher late-phase insulin) without change in early-phase insulin. We explored possible contributing factors, including changes in polysomnographic sleep and 24-h hormonal profiles. We demonstrate that the circadian system importantly contributes to the reduced glucose tolerance observed in the evening compared with the morning. Separately, circadian misalignment reduces glucose tolerance, providing a mechanism to help explain the increased diabetes risk in shift workers.circadian disruption | shift work | night work | glucose metabolism | diabetes I n healthy humans, there is a strong time-of-day variation in glucose tolerance, with a peak in the morning and a trough in the evening and night (1-6). Understanding the underlying mechanisms of the day/night variation in glucose tolerance is important for diurnally active individuals as well as shift workers, who are at increased risk for developing type 2 diabetes (7-9). The endogenous circadian system and circadian misalignment (i.e., misalignment between the endogenous circadian system and 24-h environmental/behavioral cycles) have been shown to affect glucose metabolism (4,(10)(11)(12)(13)(14). However, the relative and separate importance of the endogenous circadian system and circadian misalignment-after accounting for behavioral cycle effects (including the sleep/wake, fasting/feeding, and physical inactivity/activity cycles, etc.)-on 24-h variation in glucose tolerance is not well understood.Most species have evolved an endogenous circadian timing system that optimally times physiological variations and behaviors relative to the 24-h environmental cycle (15-17). The mammalian circadian system is comp...

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Effects of size, time of day and sequence of meal ingestion on carbohydrate tolerance in normal subjects

Cited by 92 publications

References 45 publications

Altered postprandial hormone and metabolic responses in a simulated shift work environment

Altered postprandial hormone and metabolic responses in a simulated shift work environment

Postprandial hormone and metabolic responses amongst shift workers in Antarctica

Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans

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