| 1. |
- Axelsen, Mette, 1965, et al.
(författare)
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Postprandial hypertriglyceridemia and insulin resistance in normoglycemic first-degree relatives of patients with type 2 diabetes.
- 1999
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Ingår i: Annals of internal medicine. - 0003-4819 .- 1539-3704. ; 131:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Impaired ability to eliminate lipids in the postprandial state is an atherogenic trait associated with insulin resistance. OBJECTIVE: To assess insulin sensitivity and postprandial triglyceride metabolism in prediabetic persons. DESIGN: Cross-sectional study. SETTING: Sahlgrenska University Hospital, Göteborg, Sweden. PARTICIPANTS: 13 healthy, normotriglyceridemic men with two first-degree relatives with type 2 diabetes and 13 carefully matched controls without known diabetes heredity. MEASUREMENTS: Oral glucose tolerance test, insulin sensitivity (euglycemic clamp technique), and fasting and postprandial triglyceride levels after a mixed meal. RESULTS: Relatives of persons with type 2 diabetes were insulin resistant but had normal glucose tolerance. They exhibited postprandial hypertriglyceridemia; the 6-hour triglyceride incremental area under the curve was 50% higher than that of the control group (P = 0.037). CONCLUSIONS: These healthy male first-degree relatives of patients with type 2 diabetes are insulin resistant and exhibit postprandial lipid intolerance despite having normal fasting triglyceride levels. These characteristics, which occur in the absence of glucose intolerance, are associated with an increased risk for macroangiopathy.
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| 2. |
- Carvalho, Eugénia, 1967, et al.
(författare)
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Low cellular IRS 1 gene and protein expression predict insulin resistance and NIDDM.
- 1999
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Ingår i: The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 0892-6638 .- 1530-6860. ; 13:15, s. 2173-8
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Tidskriftsartikel (refereegranskat)abstract
- We examined the gene and protein expression of IRS 1 (insulin receptor substrate 1) in adipocytes from two groups of healthy individuals with an increased propensity for non-insulin-dependent diabetes mellitus (NIDDM): those with two first-degree relatives with diabetes and another group with massive obesity. A low expression of IRS 1 (
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| 3. |
- Smith, Ulf, 1943, et al.
(författare)
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Insulin signaling and action in fat cells: associations with insulin resistance and type 2 diabetes.
- 1999
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Ingår i: Annals of the New York Academy of Sciences. - 0077-8923. ; 892, s. 119-26
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Forskningsöversikt (refereegranskat)abstract
- Adipose tissue only accounts for a relatively small proportion (< 10%) of the peripheral glucose utilization in response to insulin. However, the fat cells may still play an important role in insulin resistance and Syndrome X through, for instance, its endocrine functions (production of leptin, TNF alpha, PAI-1, etc.) and involvement in lipid metabolism (FFA release and hydrolysis of triglycerides). The fat cells are also highly sensitive to insulin and may thus be used to elucidate molecular mechanisms for insulin resistance in man. Examinations of the intracellular signaling mechanisms for insulin in fat cells from individuals with Type 2 diabetes revealed markedly lower insulin-stimulated PI3-kinase activity. This was due to a pronounced reduction in the cellular expression of the docking protein, IRS 1, whereas expression of IRS 2 was normal. However, IRS 2-associated PI3-kinase activity was only approximately one-third of that found to be associated with IRS 1 in normal cells. Downstream activation and serine phosphorylation of PKB/Akt by insulin were also markedly reduced in Type 2 diabetes. Furthermore, the dose-response curve for this effect of insulin was similar to that for glucose transport in both normal and Type 2 diabetic cells. Thus, these data show that both PI3-kinase and PKB activation by insulin are markedly reduced in Type 2 diabetes. We also examined whether an attenuated activation of PI3-kinase by insulin can be seen in non-diabetic insulin-resistant states. Approximately 30% of healthy subjects with at least two first-degree relatives with Type 2 diabetes exhibited perturbations in IRS-1 expression and signaling. These individuals were characterized by insulin resistance as well as other markers of Syndrome X. Thus, impaired IRS-1 expression and downstream signaling events in fat cells in response to insulin are associated with insulin resistance and Syndrome X.
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