Diurnal and seasonal variation in oral glucose tolerance: Studies in the antarctic

Campbell, Iain; Jarrett, R. J.; Keen, H.

doi:10.1007/bf00429838

Cited by 60 publications

(29 citation statements)

References 21 publications

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“…This variation may be explained in part also by fluctuations in vitamin D concentrations as a result of fluctuations in exposure to ultraviolet radiation [98,99].…”

Section: Vitamin D and Type-2 Dmmentioning

confidence: 99%

Vitamin D and diabetes mellitus

Danescu

Levy

2008

Endocr

157

112

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Better understanding of the physiological role of the vitamin-D system, in particular its potential effects on inflammatory and autoimmune conditions as well as on insulin secretion and possibly also on insulin resistance, increased the interest in its potential role in prevention and control of the diabetic condition, both type-1 and -2 diabetes. Both these conditions are associated with inflammation and type-1 diabetes also with an autoimmune pathology. Indeed, animal and human studies support the notion that adequate vitamin-D supplementation may decrease the incidence of type-1 and possibly also of type-2 diabetes mellitus and may improve the metabolic control in the diabetes state. However, the exact mechanisms by which vitamin-D and calcium supplementation exert their beneficial effects are not clear and need further investigation.

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“…This variation may be explained in part also by fluctuations in vitamin D concentrations as a result of fluctuations in exposure to ultraviolet radiation [98,99].…”

Section: Vitamin D and Type-2 Dmmentioning

confidence: 99%

Vitamin D and diabetes mellitus

Danescu

Levy

2008

Endocr

157

112

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“…A potential role of vitamin D in type 2 diabetes is suggested by a reported seasonal variation in the control of glycemia in patients with type 2 diabetes, being worse in the winter when hypovitaminosis D is more prevalent (Campbell et al ., 1975). Additional evidence for a role of vitamin D in type 2 diabetes comes from a large number of cross-sectional studies, which have generally reported an inverse association between vitamin D status and prevalent hyperglycemia.…”

Section: Introductionmentioning

confidence: 99%

Vitamin D and type 2 diabetes: a systematic review

2011

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Background/Objectives Vitamin D may modify the risk of type 2 diabetes mellitus. The aim of this review was to examine the association between vitamin D status and incident type 2 diabetes, and the effect of vitamin D supplementation on glycemic outcomes. Methods We performed a systematic review of English-language studies using MEDLINE through February 2011. Longitudinal cohort studies reporting associations between vitamin D status and incident type 2 diabetes, and randomized controlled trials (RCTs) of vitamin D supplementation, were included. Study characteristics and results were extracted, and study quality was assessed. Results A total of 8 observational cohort studies and 11 RCTs were included. In meta-analyses of observational studies, vitamin D intake > 500 international units (IU)/day decreased the risk of type 2 diabetes by 13% compared with vitamin D intake < 200 IU/day. Individuals with the highest vitamin D status (> 25 ng/ml) had a 43% lower risk of developing type 2 diabetes (95% confidence interval 24, 57%) compared with those in the lowest group (< 14 ng/ml). In post hoc analyses from eight trials among participants with normal glucose tolerance at baseline and in three small underpowered (n = 32–62) trials of patients with established type 2 diabetes, there was no effect of vitamin D supplementation on glycemic outcomes. In two trials among patients with baseline glucose intolerance, vitamin D supplementation improved insulin resistance. Conclusions Vitamin D may play a role in type 2 diabetes; however, to better define the role of vitamin D in the development and progression of type 2 diabetes, high-quality observational studies and RCTs that measure blood 25-hydroxyvitamin D concentration and clinically relevant glycemic outcomes are needed.

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“…A study performed in 12 men exposed to temperatures ranging from -40°C to O°C showed that blood glucose levels are lowest at the higher temperature. 5 Another study performed in a more moderate climate showed a significant seasonal variation in fasting plasma glucose." There was a mean 0·6 rnmol/L difference between the highest levels in winter and the lowest levels in spring.…”

Section: Reference Rangesmentioning

confidence: 99%

“…Recently several national groups have collaborated in an attempt to standardise the glucose load and establish a new set of criteria for the interpretation of the OGTT. The three groups, the National Diabetes Data group.l" the Euroeean Association for the Study of Diabetes, 5 and the World Health Organisation Expert Committee on Diabetes16 have all published recommendations, which although not identical have many important features in common. Their recommendations on glycaemic criteria for diagnosis of diabetes mellitus after a 75 g oral glucose load are summarised in Table 2.…”

Section: Reference Rangesmentioning

confidence: 99%