Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe an immunoradiometric assay for human intact proinsulin in serum. In this method, one monoclonal antibody, coated onto polyacrylamide beads, cross-reacts with proinsulins and insulin. A sandwich is formed with intact proinsulin, split (65-66) proinsulin, and des (64-65) proinsulin binding with an 125I-labeled monoclonal antibody specific for an epitope at the intact B-C junction of proinsulin. Because split (65-66) and des (64-65) proinsulin concentrations are very low in serum, this assay essentially measures intact proinsulin. When we used 1-mL serum samples, the mean detection limit was 0.4 pmol/L. Mean proinsulin concentrations (pmol/L) were 3.4 (range 1-9.1) in healthy fasting subjects, 28.5 (9.7-101) in patients with type 2 diabetes (treated with metformin and sulfonylureas), 5.0 (1.6-9.3) in women with hyperandrogenism and normal insulinemia, 10.3 (2.6-36) in women with hyperandrogenism and hyperinsulinemia, and 8.5 (4.8-21.3) in patients with impaired glucose tolerance.
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PMID:Immunoradiometric assay of human intact proinsulin applied to patients with type 2 diabetes, impaired glucose tolerance, and hyperandrogenism. 817 47

Insulin resistance confers increased susceptibility to NIDDM, atherosclerotic cardiovascular disease, ovarian hyperandrogenism, and possibly hypertension. Insulin resistance is largely inherited, in rare cases as a monogenic disorder or more commonly as a complex trait. The search for insulin resistance genes relies mainly on two complementary approaches: 1) positional cloning using random DNA markers present throughout the genome; and 2) the analysis of specific candidate genes. This report briefly summarizes the candidate gene approach to insulin resistance. Progress related to the analysis of genes encoding molecules that participate in insulin action is reviewed. In addition, the spectrum of potential genetic defects that might contribute to insulin resistance, both at the level of the target cell and secondarily (e.g., obesity genes), is discussed.
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PMID:Candidate genes for insulin resistance. 872 72

Insulin resistance characterizes non-insulin dependent diabetes (NIDDM). Insulin resistance may coexist in clinical syndromes with hyperestrogenism and hyperandrogenism, suggesting that the ovary may be sensitive to effects of insulin. In addition, insulin-like growth factor-I receptors, which are capable of binding insulin, have been identified in ovarian cancer tissue and are proposed to regulate cell growth. We evaluated the association between a history of diabetes mellitus and ovarian cancer in a case-control study in seven counties in Washington and in Utah (United States) during the years 1975-87. Cases included women newly diagnosed with ovarian cancer over a five-year period who were identified through population-based cancer reporting. Controls similar to cases with regard to age and county of residence were identified via household surveys or random digit dialing. The study included 595 cases and 1,587 controls. Twenty-seven cases (4.5 percent) and 72 controls (4.5 percent) reported a history of diabetes. Logistic regression analysis of the association between diabetes and ovarian cancer controlling for age, body mass index, and race resulted in an odds ratio (OR) of 0.9 (95 percent confidence interval [CI] = 0.6-1.5). The OR was not changed with further controlling for prior oral contraceptive use or prior pregnancy. None of the 20 women with nonepithelial tumors (15 of which were stromal tumors) had a history of diabetes (upper CI = 4.0). These results, together with findings of two earlier cohort studies, do not support the hypothesis that diabetes is a risk factor for epithelial ovarian cancer.
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PMID:Is diabetes mellitus a risk factor for ovarian cancer? A case-control study in Utah and Washington (United States). 881 36

Hyperandrogenism is characterized clinically by hirsutism, acne, androgens-dependent alopecia and elevated serum concentrations of androgens (testosterone and androstenedione). Polycystic ovary syndrome is the most frequent cause of hyperandrogenism. Nevertheless, the differential diagnosis includes androgen-secreting tumors of the ovary or adrenal gland. Although rare, it is important to consider this diagnosis in patients with serum testosterone concentrations greater than 7 nmol/l. A 35-year-old woman who presented with hirsutism, amenorrhea and acanthosis nigricans is described. The endocrine abnormalities included a serum testosterone concentration of 9 nmol/l and overt type II diabetes mellitus. Imaging studies, including magnetic resonance imaging and Doppler ultrasonography, did not disclose a secreting tumor. After cyproterone acetate was prescribed the serum testosterone concentration returned to normal. The recent application of modern, high-resolution diagnostic ultrasonography and magnetic resonance imaging enabled a morphologically based diagnosis in a case of severe hyperandrogenism, with no need for invasive procedures. The therapeutic response to antiandrogens is reassuring.
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PMID:A case of severe hyperandrogenism, acanthosis nigricans and over diabetes: the use of non-invasive methods for diagnosis, pathogenesis and management. 891 63

It is now clear that PCOS is often associated with profound insulin resistance as well as with defects in insulin secretion. These abnormalities, together with obesity, explain the substantially increased prevalence of glucose intolerance in PCOS. Moreover, since PCOS is an extremely common disorder, PCOS-related insulin resistance is an important cause of NIDDM in women (Table 3). The insulin resistance in at least 50% of PCOS women appears to be related to excessive serine phosphorylation of the insulin receptor. A factor extrinsic to the insulin receptor, presumably a serine/threonine kinase, causes this abnormality and is an example of an important new mechanism for human insulin resistance related to factors controlling insulin receptor signaling. Serine phosphorylation appears to modulate the activity of the key regulatory enzyme of androgen biosynthesis, P450c17. It is thus possible that a single defect produces both the insulin resistance and the hyperandrogenism in some PCOS women (Fig. 19). Recent studies strongly suggest that insulin is acting through its own receptor (rather than the IGF-I receptor) in PCOS to augment not only ovarian and adrenal steroidogenesis but also pituitary LH release. Indeed, the defect in insulin action appears to be selective, affecting glucose metabolism but not cell growth. Since PCOS usually has a menarchal age of onset, this makes it a particularly appropriate disorder in which to examine the ontogeny of defects in carbohydrate metabolism and for ascertaining large three-generation kindreds for positional cloning studies to identify NIDDM genes. Although the presence of lipid abnormalities, dysfibrinolysis, and insulin resistance would be predicted to place PCOS women at high risk for cardiovascular disease, appropriate prospective studies are necessary to directly assess this.
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PMID:Insulin resistance and the polycystic ovary syndrome: mechanism and implications for pathogenesis. 940 43

Polycystic ovary syndrome (PCOS) may be loosely defined as unexplained hyperandrogenism, with variable degrees of cutaneous symptoms, anovulatory symptoms, and obesity. The vast majority of patients with the full-blown Stein-Leventhal syndrome have functional ovarian hyperandrogenism (FOH). However, FOH often occurs without the LH excess or polycystic ovaries of classic PCOS. Functional adrenal hyperandrogenism (FAH) is often found in the syndrome, but it is less closely associated with anovulatory symptoms than is FOH. The vast majority of FOH seems to arise from abnormal regulation (dysregulation) of ovarian androgen secretion. This typically is due to escape from desensitization to luteinizing hormone (LH); this appears to occur because of a breakdown in the processes that normally coordinate ovarian androgen and oestrogen secretion so as to prevent hyperoestrogenism. Similar dysregulation of adrenal androgen secretion in response to ACTH seems to account for most FAH. Dysregulation of androgen secretion may affect the ovary alone (isolated FOH), the adrenal alone (isolated FAH), or both together. Modest insulin resistance is common in PCOS/FOH, and the resultant hyperinsulinaemia is a major candidate as the cause of the dysregulation. The hyperinsulinaemia may arise from either 'nature' (genetic defects) or 'nurture' (exogenous obesity). Although hyperinsulinaemia alone does not have an obvious effect on steroidogenesis, it may act in genetically predisposed women as a 'second hit' to unmask latent abnormalities in steroidogenesis. The ovary, the adrenal cortex, and several other organs paradoxically function as if responding to the hyperinsulinaemic state in spite of resistance to the effects of insulin on glucose metabolism. PCOS should be viewed as an early manifestation of a hyperinsulinaemic condition that will predispose to cardiovascular and metabolic complications later in life. A subset of PCOS patients appear to have not only insulin resistance but also beta-cell secretory dysfunction, which may indicate a relationship of the disorder to NIDDM. The fundamental genetic defects remain to be elucidated.
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PMID:Current concepts of polycystic ovary syndrome. 953 13

Androgenic disorders are those conditions in women characterized by excessive androgen action. They are the most common endocrinopathy of women, affecting from 10% to 20%. Signs are: persistent acne, hirsutism and androgenic alopecia, which is the female equivalent of male pattern baldness. A subgroup, those traditionally labeled as having polycystic ovary syndrome (PCOS), additionally have anovulation, as well as menstrual abnormalities and, often, obesity. Although women with androgenic disorders usually present themselves for help with the skin or menstrual changes, there are other important implications regarding their health. Women with PCOS have varying degrees of insulin resistance, and an increased incidence of Type II diabetes mellitus, as well as unfavorable lipid patterns. The presence of these risk factors is suggested by upper segment obesity, darkening of the skin, and the other skin changes that make up acanthosis nigricans. Diagnosis involves measurement of circulating androgens (of which free testosterone is most important), together with prolactin and FSH when menstrual dysfunction is present. Many women with androgenic skin changes have normal serum androgen levels, suggesting increased end organ sensitivity to androgens. Others have hyperandrogenism (of ovarian or adrenal origin). Treatment is usually successful in controlling acne, reducing hirsutism and stabilizing, or partially reversing, androgenic alopecia. Pharmacological approaches involve suppressing androgen levels, for example, the use of an appropriate oral contraceptive, or antagonizing androgen action with several medications that have this activity. Unfortunately, most women with androgenic disorders are frustrated in their efforts to obtain medical help. Understanding androgenic disorders will enable the physician to significantly help the majority of women with these conditions.
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PMID:Androgens and women's health. 960 8

Polycystic ovary syndrome (PCOS) is a common disorder in premenopausal women and is characterized by hyperandrogenic chronic anovulation. The cause is unknown. PCOS is associated with significant insulin resistance as well as with defects in insulin secretion. These abnormalities place these women at substantial risk for developing type 2 diabetes mellitus. A defect in insulin-mediated receptor autophosphorylation has been found in a substantial proportion of PCOS women. Both PCOS and the insulin resistance that accompanies it appear to have major genetic components. Family studies of PCOS have supported this, although they suffer from incomplete phenotyping of probands and first-degree relatives. The phenotype in males and nonreproductive age females is uncertain. Despite the shortcomings of the family studies of PCOS, they have consistently indicated familial clustering and suggested that the mode of inheritance is dominant. Our initial studies of 50 families of PCOS probands indicate that 24% of sisters are affected with PCOS. There also appears to be an intermediate phenotype of sisters with regular menstrual cycles who are hyperandrogenic per se (22% of sisters). Additionally, there appears to be a major familial defect, with 50% of first-degree relatives having glucose intolerance (impaired glucose tolerance by oral glucose tolerance test or type 2 diabetes mellitus). These findings suggest that hyperandrogenism in females and glucose intolerance may be genetic traits in PCOS kindreds. Systematic phenotyping will allow assignment of affected status for eventual linkage analysis.
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PMID:Phenotype and genotype in polycystic ovary syndrome. 976 10

Almost two decades of research have greatly increased our knowledge in the complex field of metabolic aberrations in polycystic ovary syndrome, but still many problems remain unsolved. The statistical association between insulin levels and androgens originally put the focus on possible direct cause-and-effect relationships between these factors. Indeed there is evidence that insulin may affect ovarian functions in multiple ways, presumably in some cases causing anovulation and hyperandrogenism. Clearly, insulin may increase biologically active testosterone through reducing SHBG levels. Conversely, major increases in androgen levels may induce muscular changes leading to reduced insulin-mediated glucose uptake. There are suggestions of increased steroidogenesis in both ovarian and adrenal pathways, with the net result of increased androgen production. There are also findings supporting increased corticosteroid production, which could contribute to insulin resistance directly or through promoting accumulation of abdominal fat, a typical feature of over-weight women with PCOS. Free fatty acids, released in great amounts from abdominal fat, may induce insulin resistance. Insulin resistance may also be due to a primary aberration in the insulin receptor. Putatively increased serine phosphorylation may cause both impairment of the insulin signal and increased 17,20 lyase activity, thus suggesting a common cause for insulin resistance and increased androgen production. There are also findings supporting a high prevalence of beta-cell dysfunction in PCOS, ranging from increased insulin secretion, not explained by insulin resistance or BMI, to failing beta-cell function, mainly in obese women during progress to glucose intolerance and NIDDM. Recent genetic findings also support a multifactorial genesis to PCOS, notably with positive findings both in genes regulating steroidogenesis and insulin secretion. It is suggested that PCOS is the result of "thrifty" genes, providing advantages in times of shortage of nutrition such as muscular strength, moderate abdominal fatness and decreased insulin sensitivity, i.e. an anabolic, energy saving constitution. However, when this constitution is exposed to unlimited food supplies and modern sedentary life style a full-blown PCOS with insulin resistance and infertility is triggered, presumably via several mechanisms, which follow a logical amplification system between two basic anabolic hormones, insulin and testosterone.
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PMID:Polycystic ovary syndrome and insulin resistance: thrifty genes struggling with over-feeding and sedentary life style? 985 13

The syndromes of extreme severe insulin resistance are mainly caused by genetic defects of the insulin receptor gene (Type A syndrome, Leprechaunism, and Rabson-Mendenhall syndrome) or by the presence of circulating autoantibodies that disrupt the normal functions of the insulin receptor (Type B syndrome). These syndromes are characterized by the hyperinsulinemia and severe insulin resistance and in most cases accompanied by impaired glucose tolerance and diabetes mellitus. The clinical features common to these syndromes are acanthosis nigricans, hyperandrogenism and ovarian dysfunction. On the other hand, an important distinguishing typical feature in type B syndrome is evidence of other autoimmune disorders. [These syndromes can be a contributory causes of insulin resistance in a subpopulation with NIDDM.]
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PMID:[Syndromes of severe insulin resistance]. 1019 43


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