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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Low birth weight is associated with an increased risk in adult life of type 2 diabetes, hypertension and cardiovascular disease (CVD). The fetal insulin hypothesis postulates that genes involving insulin resistance could effect birth weight and disease in later life (Hattersley, 1999). Besides insulin, there is extensive evidence that insulin-like growth factor-I and -II (IGF-I, IGF-II) play an important role in fetal growth. We hypothesized that minor genetic variation in the IGF-I gene could influence pre- and postnatal growth. Three microsatellite markers located in the IGF-I gene in 124 short children (height < -1.88 SDS) who were born small for gestational age (SGA) and their parents were studied. SGA was defined as both a birth weight and birth length below -1.88 SDS for gestational age. Two polymorphic markers showed transmission disequilibrium. Allele 191 of the IGF1.PCR1 marker was transmitted more frequently from parent to child (chi(2) = 4.8 and p = 0.02) and allele 198 of the 737/738 marker was transmitted less frequently from parent to child (chi(2)= 4.5 and p = 0.03). Children carrying the 191-allele had significantly lower IGF-1 levels than children not carrying this allele (-1.1 SDS vs. -0.05 SDS; p = 0.03). Also, head circumference SDS remained smaller in children with allele 191 compared to children without allele 191 (-2.1 SDS vs. -0.9 SDS; p = 0.003). Our results show that genetically determined low IGF-I levels may lead to a reduction in birth weight, length and head circumference and to persistent short stature and small head circumference in later life (proportionate small). Since low IGF-I levels are associated with type 2 diabetes and CVD, we propose that the IGF-I gene may provide a link between low birth weight and such diseases in later life.
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PMID:Polymorphism in the IGF-I gene: clinical relevance for short children born small for gestational age (SGA). 1205 Feb 40

The effects of circulating insulin-like growth factor (IGF)-I on increasing insulin sensitivity are well recognized. IGF-I may have a further important role in maintaining beta-cell mass, and lower IGF-I activity could explain links between small size at birth and risk of type 2 diabetes in short, obese adults. In the representative Avon Longitudinal Study of Pregnancy and Childhood birth cohort, whereas insulin sensitivity is related to early postnatal weight gain, insulin secretion is related to IGF-I level and statural growth. Adult studies suggest that lower IGF-I levels at baseline predict increased risk for developing impaired glucose tolerance and type 2 diabetes. A common genetic polymorphism in the IGF1 gene could influence size at birth, postnatal growth and type 2 diabetes risk, but results of studies have been inconsistent. Extrapolation of these data to short children born small for gestational age is complex. Some have evidence of IGF-I and insulin resistance, suggesting inherent defects in IGF-I signalling. These children have poor growth responses to growth hormone (GH) therapy and perhaps the highest type 2 diabetes risk. Where these metabolic abnormalities are less severe, responses to GH therapy are good and diabetes risk may then depend on other genetic factors, indicated by a family history of diabetes or origin from ethnic groups with high diabetes prevalence.
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PMID:Serum insulin-like growth factor-I levels and potential risk of type 2 diabetes. 1467 10

We have evaluated the possible association of polycystic ovary syndrome (PCOS) with 15 genomic variants previously described to influence insulin resistance, obesity, and/or type 2 diabetes mellitus. Seventy-two PCOS patients and 42 healthy controls were genotyped for 15 variants in the genes encoding for paraoxonase (three variants), plasma cell differentiation antigen glycoprotein, human sorbin and SH3 domain containing 1, plasminogen activator inhibitor-1, peroxisome proliferator-activated receptor-gamma2, protein tyrosine phosphatase 1B (two variants), adiponectin (two variants), IGF1, IGF2, IGF1 receptor, and IGF2 receptor. Compared with controls, PCOS patients were more frequently homozygous for the -108T variant in paraoxonase (36.6% vs. 9.5%; P = 0.002) and homozygous for G alleles of the ApaI variant in IGF2 (62.9% vs. 38.1%; P = 0.018). Paraoxonase is a serum antioxidant enzyme and, because -108T alleles result in decreased paraoxonase expression, this increase in oxidative stress might result in insulin resistance. G alleles of the ApaI variant in IGF2 may increase IGF2 expression, and IGF2 stimulates adrenal and ovarian androgen secretion. In conclusion, the paraoxonase -108 C-->T variant and the ApaI polymorphism in the IGF2 gene are associated with PCOS and might contribute to increased oxidative stress, insulin resistance, and hyperandrogenism in this prevalent disorder.
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PMID:Association of the polycystic ovary syndrome with genomic variants related to insulin resistance, type 2 diabetes mellitus, and obesity. 1518 Oct 35

Insulin-like growth factor I (IGF-I) has significant structural homology with insulin. IGF-I has been shown to bind to insulin receptors to stimulate glucose transport in fat and muscle, to inhibit hepatic glucose output and to lower blood glucose while simultaneously suppressing insulin secretion. However, the precise role of IGF-I in maintaining normal glucose homeostasis and insulin sensitivity is not well defined. Studies in patients with diabetes have shown that in insulin-deficient states, serum IGF-I concentrations are low and increase with insulin therapy. Similarly, administration of insulin via the portal vein results in optimization of plasma IGF-I concentrations. A patient with an IGF1 gene deletion was shown to have severe insulin resistance that improved with IGF-I therapy. Studies conducted in experimental animals have shown that if IGF-I synthesis by the liver is deleted, the animals become insulin-resistant, and this is improved when IGF-I is administered. Likewise, deletion of the IGF-I receptor in muscle in mice induces severe insulin resistance. Administration of IGF-I to patients with type 2 diabetes mellitus has been shown to result in an improvement in insulin sensitivity and a reduction in the requirement for exogenously administered insulin to maintain glucose homeostasis. A polymorphism in the IGF1 gene that has been shown to reduce serum IGF-I results in an increased prevalence of type 2 diabetes. Taken together, these findings support the conclusion that IGF-I is necessary for normal insulin sensitivity, and impairment of IGF-I synthesis results in a worsening state of insulin resistance.
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PMID:Role of insulin-like growth factor iin maintaining normal glucose homeostasis. 1576 Dec 37

The effects of circulating insulin-like growth factor I (IGF-I) on glucose metabolism are well recognized. IGF-I is also important in maintaining beta-cell mass and regulating endogenous growth hormone (GH) levels. Low IGF-I levels could explain links between small birth size and the risk of developing type 2 diabetes mellitus in short, obese adults. In a recent prospective study, childhood insulin secretion was related to IGF-I levels and statural growth, whereas insulin sensitivity was related to early post-natal weight gain. Common genetic polymorphisms in the IGF1 gene have been linked to small birth size, post-natal growth and future diabetes risk, but these results have been inconsistent. Recent adult studies have demonstrated that lower baseline IGF-I levels predict the subsequent development of impaired glucose tolerance (IGT), type 2 diabetes and cardiovascular disease. Administration of low-dose GH therapy, at a dose that minimizes the lipolytic effects of GH and has the ability to increase IGF-I levels, enhances insulin sensitivity in young healthy adults and in GH-deficient adults and increases insulin secretion in individuals with IGT. Whether the administration of low-dose GH, recombinant IGF-I or combined IGF-I/IGF-binding protein 3 therapy prevents future development of IGT or type 2 diabetes in high-risk normoglycaemic and GH-deficient individuals merits further long-term studies.
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PMID:Insulin-like growth factor I and impaired glucose tolerance. 1576 Dec 41

Polycystic ovary syndrome (PCOS) is a common heterogenous endocrine disorder associated with amenorrhoea (or oligomenorrhoea), hyperandrogenism, hirsutism, obesity, insulin resistance, and an approximately 7-fold increased risk of type 2 diabetes mellitus (NIDDM - non-insulin dependent diabetes mellitus). It is a leading cause of female infertility. The prevalence of PCOS among reproductive-age women has been estimated at 4%-12%. Familial aggregation of this syndrome is well established. There are also ethnic and racial variations in the prevalence of the syndrome and its symptoms. Multiple biochemical pathways have been implicated in the pathogenesis of PCOS. Several genes from these pathways have been tested include genes involved in steroid hormone biosynthesis and metabolism (StAR, CYP11, CYP17, CYP19 HSD17B1-3, HSD3B1-2), gonadotropin and gonadal hormones action (ACTR1, ACTR2A-B, FS, INHA, INHBA-B, INHC, SHBG, LHCGR, FSHR, MADH4, AR), obesity and energy regulation (MC4R, OB, OBR, POMC, UCP2-3), insulin secretion and action (IGF1, IGF1R, IGFBPI1-3, INS VNTR, IR, INSL, IRS1-2, PPARG) and many others. Most women with PCOS, both obese and lean, have a degree of insulin resistance. The minisatellite of insulin gene (INS VNTR), especially class III alleles and III/III genotypes might not only determine the predisposition to anovulatory PCOS but also the concomitant risk for development of type 2 diabetes. The function of the insulin receptor (IR) is probably normal in woman with PCOS. However abnormal serine phosphorylation in the receptor may impair signal transduction accounting for a post-binding defect in insulin action. Serine phosphorylation is also involved in the postranslational regulation of 17,20-lyase activity (CYP17). There may be a common aetiology for both insulin resistance and hyperandrogenism. Polymorphic alleles of both IRS-1 and IRS-2 (insulin receptor substrate 1 - 2), alone or in combination, may have a functional impact on the insulin-resistant component of PCOS. There is no evidence to suggest that follistatin gene polymorphisms play a role in the pathogenesis of insulin resistance in PCOS women. PCOS appears to be associated with the absence of the four-repeat-units allele in a polymorphic region of pentanucleotide (TTTTA)n repeats within CYP11A gene, which encodes cytochrome P450scc. It has been hypothesized that up-regulation of this enzyme could lead to increased androgen production. There is no evidence of any association of alleles of CYP19 gene (encoding cytochrome P450arom) with PCOS. Association exists between androgen receptor gene (AR) polymorphisms an androgens action in PCOS. Increased hirustism and decreased CAG repeat length within AR gene has been also demonstrated in women with normal testosterone levels. Expression of estrogen receptor (ERs) as well as 5-alpha-reeducates (SRD5A1-2 genes) activity was analysed in granulosa (GC) and theca cells (TC). The results of this study demonstrate that there are significant alterations in the expression of ERalpha and ERbeta in PCOS that may be related to abnormal follicular development. On the other hand elevated SRD5A activity in polycystic ovaries supported the hypothesis that 5-alpha-reduced androgens may play a role in the pathogenesis of the syndrome. The genetic aetiology of PCOS remains unknown. There are a number of interlinking factors that affects expression of PCOS. Single cause of PCOS is unlikely. Other possible mechanisms in pathogenesis of PCOS are discussed.
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PMID:[Genetic aspects of polycystic ovary syndrome]. 1635 Jul 21

Insulin-like growth factor (IGF) 1 is a member of a family that is involved in growth, development, cell differentiation, and metabolism. IGF1, IGF2 and insulin act primarily through tyrosine-kinase-linked receptors--the IGF1 receptor (IGF1R) and insulin receptor (IR). The IGF1R binds IGF1 and IGF2 with high affinity and the IR binds insulin with high affinity; however, since both receptors share a high degree of structural and functional homology, the IGF1R can bind insulin and the IR can bind the IGFs with reduced affinity. These two receptors can, moreover, form heterodimers, which bind both ligands. Upon binding to the receptors, cascades of tyrosine and serine kinases are stimulated to facilitate growth or metabolism. The IGF2 receptor is a scavenger receptor, and is, therefore, not involved in mediation of growth or metabolic effects of the IGF family and will not be discussed in the current article. IGF1 is a major gene target of growth hormone and its product mediates many of the actions of growth hormone on growth and development; however, IGF1 has actions distinct from those of growth hormone in carbohydrate, lipid, and protein metabolism. For example, excess growth hormone causes insulin resistance and hyperglycemia, whereas IGF1 has insulin-like effects that reduce blood glucose levels and has been used experimentally to treat both type 1 and type 2 diabetes.
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PMID:Mechanisms of disease: metabolic effects of growth hormone and insulin-like growth factor 1. 1731 38

Insulin resistance and obesity are underlying causes of type 2 diabetes and therefore much interest is focused on the potential genes involved. A series of anthropometric and metabolic characteristic were measured in 240 MZ and 112 DZ twin pairs recruited from the East Flanders Prospective Twin Survey. Microsatellite markers located close to ABCC8, ADIPOQ, GCK, IGF1, IGFBP1, INSR, LEP, LEPR, PPARgamma and the RETN gene were genotyped. Univariate single point variance components linkage analyses were performed using two methods: (1) the standard method, only comprising the phenotypic and genotypic data of the DZ twin pairs and (2) the extended method, also incorporating the phenotypic data of the MZ twin pairs. Suggestive linkages (LOD > 1) were observed between the ABCC8 marker and waist-to-hip ratio and HDL-cholesterol levels. Both markers flanking ADIPOQ showed suggestive linkage with triglycerides levels, the upstream marker also with body mass and HDL-cholesterol levels. The IGFBP1 marker showed suggestive linkage with fat mass, fasting insulin and leptin levels and the LEP marker showed suggestive linkage with birth weight. This study suggests that DNA variants in ABCC8, ADIPOQ, IGFBP1 and LEP gene region may predispose to type 2 diabetes. In addition, the two methods used to perform linkage analyses yielded similar results. This was however not the case for birth weight where chorionicity seems to be an important confounder.
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PMID:Anthropometry, carbohydrate and lipid metabolism in the East Flanders Prospective Twin Survey: linkage of candidate genes using two sib-pair based variance components analyses. 1882 33

Background Puberty is a period of rapid growth associated with metabolic, hormonal, and body composition changes that can influence risk factors for chronic diseases such as type 2 diabetes. Objective To evaluate body composition and insulin sensitivity (IS) modifications throughout puberty in a large group of obese Caucasian subjects. Methods Five hundred and nineteen obese subjects (4-19 years), grouped according to gender and Tanner stage (T), underwent oral glucose tolerance test. Quantitative insulin check index (QUICKI) and ISI were calculated as indexes of IS. In 309 subjects, body composition by dual-energy X-ray absorptiometry, IGF1, adiponectin, and leptin were also evaluated. Results Body composition modifications were sexually dimorphic, with girls not modifying fat and lean percentage and fat distribution (P>0.15), and boys decreasing fat percentage and increasing lean percentage and central fat depot (P<0.001) across Ts. IS decreased during mid-puberty and returned to prepubertal levels by the end of puberty. Girls showed lower IS than boys (P<0.01 and =0.03 for QUICKI and ISI respectively). In multivariate analysis factors that negatively influenced IS, independently from T or age, were total fat mass and central fat depot in girls (P<0.05 and <0.01, respectively), total fat and lean mass in boys (P<0.01). IGF1, adiponectin, and leptin were not related to pubertal IS. Conclusions In obese Caucasian subjects, further decrease of IS observed during puberty is a transient phenomenon. Factors that independently from T or age influence IS are central fat depot in girls, lean amount in boys, and total fat mass in both sexes.
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PMID:Sexual dimorphism of body composition and insulin sensitivity across pubertal development in obese Caucasian subjects. 1922 Nov 73

Avoiding age-related disease until late in life is key to 'successful' ageing. Over 300 genome-wide association study papers have been published. Over 50 variants have already been identified as associated with four key age-related diseases, namely cardiovascular disease, type 2 diabetes, osteoporosis and prostate cancer. We review these findings with reference to pathways linked to ageing, including cell cycle control or cell senescence, oxidative stress, insulin, IGF1 and other endocrine signalling, and inflammation. Many variants are disease specific or of unknown function. Of the remainder, those with functions likely to be relevant to ageing are predominantly in cell cycle control and therefore tissue repair. Three loci associated with two or more age-related diseases have been identified, two apparently related to cell cycle control. The third shared locus (near TERT), may be involved in telomerase activity and is associated with several environmentally caused age-related cancers. These findings challenge current ideas, suggesting large numbers of cell type specific effects, often driven by regulatory rather than coding changes. They also confirm the central role of cell cycle and re-growth as a key pathway underlying the human variation in successful ageing.
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PMID:Human genetic variations: Beacons on the pathways to successful ageing. 1958 Aug 24


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