In support of an early polypharmacy approach to the treatment of type 2 diabetes.

Type 2 diabetes (T2DM) is a multifaceted disease, characterized by hyperglycaemia, resulting from a combination of insulin resistance, impaired incretin action and ß-cell dysfunction leading to relative insulin deficiency. Although traditional anti-diabetes agents improve hyperglycaemia, they do so at a cost, which may entail hypoglycemia and increased body weight; exacerbating dyslipidemia, hypertension and components of insulin resistance and metabolic syndrome associated with T2DM-potentially increasing cardiovascular risk. At diagnosis, many patients with T2DM are treated with medical nutritional therapy (MNT) and exercise, then single or multiple oral anti-diabetes agents until treatment failure, when insulin is used. This strategy has been challenged by recommendations for polypharmacy approaches to the treatment of T2DM, as current strategies are unable to improve multiple aspects of the disease, nor are they likely to address underlying pathophysiology. Although the 2009 American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) treatment algorithm recommends a stepwise approach with MNT and metformin, later adding oral agents, incretin-based therapies or insulin, some experts have recommended a more aggressive approach. In his 2008 ADA Banting Lecture, Dr. Ralph DeFronzo recommended early treatment with metformin, TZD and exenatide at initiation of therapy. The authors' of this article recommend an aggressive early polypharmacy approach addressing underlying pathophysiology, including the incretin defect-with MNT and exercise, metformin and an incretin-based therapy and/or basal insulin if glycemic goal is not achieved within 3 months. This approach attempts to modify the disease, aiming for tight glycemic control, weight loss, reduced hypoglycemia, improvements to hypertension, dyslipidemia and insulin resistance-and improved cardiovascular outcomes.

Screening mammogram utilization in women with diabetes.

OBJECTIVE: To determine whether women with diabetes undergo fewer screening mammograms than matched control subjects. RESEARCH DESIGN AND METHODS: A total of 424 women with diabetes aged 50-75 years who received their primary care from general internists at a large Midwestern multispecialty group practice were retrospectively studied for frequency of mammography from August 1997 to January 2000. Two control subjects without diabetes (n = 845) were matched to each case by age, sex, provider, and date of visit. The main outcome measure was the percentage of subjects undergoing mammography 1 year before and 30 days after an index date, defined as the most recent health care visit after August 1997 and before January 2000. RESULTS: Analysis by conditional logistic regression demonstrated that women with diabetes had significantly lower rates of mammograms than control subjects (78.1 vs. 84.9%, respectively; odds ratio 0.63, P = 0.002). After adjusting for insurance status and race, women with diabetes continued to have significantly lower rates of mammography (odds ratio 0.70, P = 0.027). CONCLUSIONS: Women with diabetes were significantly less likely to undergo screening mammography than control subjects. Considering the increasing incidence of diabetes and the equal incidence of malignancy in women with and without diabetes, it would be beneficial to improve breast cancer screening in this population.

Lack of an association between alleles of interleukin-1 alpha and interleukin-1 receptor antagonist genes and Graves' disease in a North American Caucasian population.

Although an association between the human leukocyte antigen (HLA) allele DR3 and Graves' disease (GD) is well documented, the potential role of non-HLA-linked alleles in susceptibility to GD is an area of active investigation. In an attempt to study the potential role of two non-HLA susceptibility alleles in GD and Graves' ophthalmopathy, we examined 286 North American Caucasian individuals (145 normal controls and 141 individuals with GD) for the presence of the A2 allele of the interleukin-1 (IL-1) receptor antagonist gene. In addition, we examined a subset of this population (83 normal controls and 89 individuals with GD) for a specific polymorphism within exon 5 of the IL-1 alpha gene. We found the A2 allelic frequencies (0.25 and 0.23, respectively) and carriage rates (43% and 41%, respectively) in the two groups to be nearly identical. However, findings in the subgroup of patients with the extrathyroidal manifestations of GD (Graves' ophthalmopathy, pretibial dermopathy, and acropachy) suggested a trend toward a higher prevalence of the A2 allele in patients with more severe disease. The allelic frequency (0.28) and carriage rate (47%) of the IL-1 alpha exon 5 polymorphism in individuals with GD were nearly identical to those of the control population (0.28% and 45%, respectively). In summary, we were unable to demonstrate an association between these alleles and GD in our study population. We conclude that neither the A2 allele of the IL-1 receptor antagonist gene nor the IL-1 alpha exon 5 polymorphism confers increased susceptibility to GD.

Lack of an independent association between the human leukocyte antigen allele DQA1*0501 and Graves' disease.

The association between the human leukocyte antigen (HLA) serotype DR3 and Graves' disease (GD) in Caucasian populations is well known. However, an even stronger association has been reported recently, especially in the male population, between the closely linked HLA allele DQA1*0501 and GD. We postulated that the reported association between DQA1*0501 and GD may be a result of the linkage of this allele with DR3 and may not represent an independent association. Accordingly, we screened a population of North American Caucasians (n = 218), including patients with GD (n = 101, 32 males, 69 females) and individuals with documented normal thyroid function (n = 117, 51 males, 66 females), for the presence of the DQA1*0501 allele and those alleles corresponding to the DR3 serotype (DRB1*03). Screening was accomplished using sequence specific PCR. A significant association was documented in the total study population between DR3 positivity and GD (P = 0.0002), but not between DQA1*0501 positivity and GD (P = 0.06). After gender stratification, significant associations were found only in the female population (DR3, P = 0.0004; DQA1*0501, P = 0.012) and not in the male population (DR3, P = 1.0; DQA1*0501, P = 1.0). Additionally, in those DR3 negative female subjects (n = 100), there was no independent association between DQA1*0501 positivity (n = 26) and GD (p = 0.82). P-values were corrected, where appropriate, for gender stratification and/or the number of HLA alleles tested. In conclusion, our results demonstrate a lack of independent association between the presence of the HLA allele DQA1*0501 and GD. We suggest that the apparent association between this allele and GD in the female population may be the result of its' close linkage to DR3.

A polymorphism in the extracellular domain of the thyrotropin receptor is highly associated with autoimmune thyroid disease in females.

We and others have described previously a polymorphism at the first position of codon 52 (C52 --> A52) of the human thyrotropin receptor (hTSHr) gene. To determine its potential significance, we studied female (n = 100) and male (n = 25) patients with autoimmune thyroid disease (Graves' disease, n = 91; Hashimoto's thyroiditis, n = 34) and normal individuals [n = 121, female (n = 69), male (n = 52)]. Screening was performed using AciI restriction enzyme digestions of PCR-amplified genomic DNA. All codon 52 polymorphisms were verified by direct DNA sequencing. Data were analyzed using Chi-square or Fisher exact tests and p-values were corrected for multiple comparisons. Our studies demonstrated that this polymorphism is highly associated with autoimmune thyroid disease in the female population (corrected p = 0.008). We found no such association in the male population. Within females, there was a greater association between Graves' disease and the polymorphism (corrected p = 0.017) than between Hashimoto's thyroiditis and the polymorphism (corrected p = 0.090). The polymorphism was present in a higher proportion of Graves' disease patients with Graves' ophthalmopathy and pretibial dermopathy (40%) or Graves' ophthalmopathy, pretibial dermopathy, and acropachy (60%), than in patients with Graves' disease alone (15%), or Graves' disease and Graves' ophthalmopathy alone (17%). In conclusion, a polymorphism (C52 --> A52) of the hTSHr is associated with autoimmune thyroid disease in females.

Multivariate analysis of HLA loci in conjunction with a thyrotropin receptor codon 52 polymorphism in conferring risk of Graves' disease.

Recent reports have suggested that the HLA alleles DRB3*0101 or DQA1*0501 confer greater susceptibility to Graves' disease than does the DR3 allele. We have reported previously that a non-HLA-linked allele, a polymorphism in codon 52 of the human thyrotropin receptor gene, is highly associated with Graves' disease in females. To determine which of these four susceptibility alleles confers greater independent risk for the development of Graves' disease, we analyzed the alleles in 134 North American Caucasian females who have Graves' disease (n = 69) or are normal controls (n = 65) in a logistic regression model. While we found each of these alleles to be associated with Graves' disease when analyzed independently (corrected p < 0.01 for each of 4 alleles tested), only DR3 (p = 0.0001) and the thyrotropin receptor polymorphism (p = 0.0060) maintained a statistically significant independent association when assessed in conjunction with each of the other alleles in a logistic model. We conclude that DR3 confers the greatest susceptibility to Graves' disease (odds ratio = 7.6) of the alleles within the HLA locus, and that any association between DRB3*0101 or DQA1*0501 and Graves' disease may be a result of the tight linkage disequilibrium between these alleles and DR3. In addition, we found the non-HLA-linked thyrotropin receptor codon 52 polymorphism to confer significant independent risk of Graves' disease (odds ratio = 9.0). Further, because 6 of 6 individuals who possessed both DR3 and the thyrotropin receptor polymorphism had Graves' disease, while no individual in the normal control group possessed both alleles, study of a larger population to assess the potential synergism between these 2 alleles is warranted.

Normal function in vivo of a homozygotic polymorphism in the human thyrotropin receptor.

We have demonstrated previously and association between a polymorphism in the human thyrotropin receptor gene and an increased prevalence of autoimmune thyroid disease in individuals bearing this polymorphic allele. The polymorphism involves the nucleotide base substitution of a cytosine for the wild-type adenine at the first position of codon 52 and is found generally in the heterozygotic state. Such change results in the substitution of a threonine for the wild-type proline at this position in the receptor protein sequence. The resulting protein would lack a beta turn (at position 52) in a potential loop conformation, and thus would have a significantly altered three-dimensional conformation. The biologic consequences of this conformational change in the receptor are unknown, but may involve altered function or immunogenicity. We report here two individuals with normal thyroid function who are homozygous for the thyrotropin receptor polymorphism, suggesting that the altered receptor is able to respond normally to thyrotropin with respect to the maintenance of the euthyroid state.