Clinical Endocrinology in the near future: a post-modern challenge

Strategic reflections of the Spanish Society of Endocrinology and Nutrition on the future of the speciality in the period 2018-2022

Endocrine diseases are experiencing an important increase in their prevalence, due to causes of various kinds, including the epidemic of obesity and malnutrition, the aging of the population, but also the effect of endocrine disruptors, among others. On the other hand, new technologies, both in terms of molecular and genetic analysis, image and new therapeutic devices, require that the endocrine professional community in Spain must be in constant training. The connection with patients through their associations, increasingly active, and with the civil society in general, the professional commitment and demand of various social groups for a modern and equitable care, and to carry out research that facilitates the achievement of advances for patients, forces the specialist in endocrinology and nutrition and the Spanish Society of Endocrinology and Nutrition (SEEN) to position themselves and respond to all these challenges. In this document, the SEEN presents its proposals and its strategy until 2022.

Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report

There is a frequently encountered subset of hypothyroid patients who are refractory to standard thyroid hormone replacement treatment and require unexpectedly high doses of levothyroxine. In addition to clinical situations where hypothyroid patients are non-compliant, or where there is the possibility of excipient-induced disease exacerbation (gluten/celiac disease), therapeutic failure may be due to impaired absorption of the administered drug. The common approach to managing patients with unusual thyroxine needs is to escalate the dose of levothyroxine until targeted TSH levels are achieved. This approach can increase the risk for prolonged exposure to supratherapeutic doses of levothyroxine, which increase the chances of adverse outcomes. Repeated adjustments of levothyroxine can also escalate the costs of treatment, as frequent office visits and laboratory tests are required to determine and maintain the desired dose. Clinicians should take a systematic approach to managing patients whom they suspect of having treatment-refractory hypothyroidism. This may include searching for, and adjusting, occult medical conditions and/or other factors that may affect the absorption of levothyroxine, before up-titrating the dose of traditional levothyroxine therapy. Depending on the underlying pathology, another approach that may be considered is to try alternative formulations of levothyroxine that are less susceptible to intolerance issues related to excipients, or, in some cases, to malabsorption. The early discovery of these factors via a thoughtful patient work-up may avoid unnecessary thyroid medication adjustments and their consequences for both patients and clinicians.

Vitamin D receptor gene polymorphisms/haplotypes and serum 25(OH)D3 levels in Hashimoto's thyroiditis

Vitamin D deficiency and/or reduced function, as per certain polymorphisms of the vitamin D receptor (VDR) gene, have been related to several autoimmune disorders. The present study was aimed to investigate the association of Hashimoto's thyroiditis with vitamin D status and functional polymorphisms (SNPs) of the VDR gene. In this case-control study, 200 euthyroid subjects were enrolled: 100 newly diagnosed HT patients (87 F, 13 M; mean age ± SD 42 ± 15 year) and 100 healthy individuals, matched for age, sex, BMI, and month of blood sampling. Serum 25(OH)D₃ was measured by HPLC. The VDR SNPs BsmI, ApaI, and TaqI, in strong linkage disequilibrium with each other, were detected by restriction fragment length polymorphism-PCR. The prevalence of vitamin D deficiency in HT patients was significantly higher than that in the control group (70 vs 18.2 %; p < 0.0001), and median serum 25(OH)D₃ level was significantly lower in HT patients than controls (median value: 16.2 vs 37.4 ng/ml; p = 0.026). Moreover, there was a significant inverse correlation between serum 25(OH)D₃ and TPOAb concentration (r = -0.669; p = 0.034). Contrarily, the genotype distribution of the studied SNPs was not different in the two groups (BsmI p = 0.783; ApaI p = 0.512; TaqI p = 0.471), as was the allelic frequency [f(B) p = 0.776, f(b) p = 0.887; f(A) p = 0.999, f(a) p = 0.999; f(T) p = 0.617; f(t) p = 0.617]. The present study first investigates newly diagnosed untreated HT and suggests that vitamin D deficiency may contribute to HT development and/or progression, acting as an environmental trigger, while the VDR locus does not appear to be involved in conditioning the genetic susceptibility to the disease, at least in Caucasians.

TP53 polymorphism may contribute to genetic susceptibility to develop Hashimoto's thyroiditis

PURPOSE

p53, which is encoded by the tumor suppressor gene TP53, plays a crucial role in the regulation of mechanisms of cell cycle arrest and apoptosis. Some SNPs of TP53, involving a different apoptotic ability of p53, have been associated with increased susceptibility to develop autoimmune diseases as well as cancer. We investigated the genotypic distribution of TP53 exon 4 SNPs in a cohort of Caucasian patients affected by Hashimoto's thyroiditis (HT).

METHODS

Peripheral blood for DNA extraction was collected from 109 Caucasian unrelated subjects, 79 HT patients and 30 healthy controls. SNPs analysis was carried out by amplification and sequencing of exon 4 TP53.

RESULTS

For the Pro72Arg (rs 1042522) SNP we found these rates in HT patients: 11.4% wild-type C/C (Pro72Pro), 24.0% heterozygous G/C (Pro72Arg), 64.6% homozygous G/G (Arg72Arg). The corresponding rates in healthy controls were 10, 46.7 and 43.3%, respectively. Thus, significantly different were G/C heterozygosity (24.0 vs 46.7 %, p = 0.039) and G/G homozygosity (64.6 vs 43.3%, p = 0.042). These differences were also confirmed when comparing our study population to published Caucasian control groups. The other described SNPs (Pro34Pro rs 11575998, Pro36Pro rs1800370, Pro47Ser rs1800371, and Arg110Leu rs 11540654) were absent or very rare in our study population.

CONCLUSIONS

Our preliminary data, the first on a Caucasian population, indicate an increased prevalence of the homozygous genotype Arg/Arg and a decreased prevalence of heterozygous genotype Arg/Pro of rs 1042522 in HT patients compared to controls, suggesting that such SNP may contribute to confer susceptibility to HT.