[Iodine Nutritional Status and Prevalence of Thyroid Disorders among Adults in Chengdu].

Objective: To investigate the prevalence of thyroid disorders, iodine nutritional status and relevant risk factors among adults in Chengdu city on the basis of two population-based surveys, one conducted between 2016 and 2017 and the other, between 2019 and 2020, and to provide references for making health-related administrative decisions. Methods: Two population-based sampling surveys were conducted. The first one was done between October 2016 and December 2017, using stratified cluster random sampling to select subjects from 2 urban and 2 rural communities in Chengdu. Then, between December 2019 and February 2020, sequential cluster sampling was used to select subjects from communities in the peripheral regions of Longquanyi District, Chengdu. Both surveys covered natural populations of people who were 18 or older and who met the inclusion criteria. In the first survey, questionnaires, physical examination, thyroid ultrasound, and examinations of serum thyroid biochemical markers and urine iodine were performed, while in the second survey, only questionnaire concerning thyroid disorders and physical examination were performed. Statistical analysis of the nutritional status of iodine, the prevalence of thyroid disorders, and potential risk factor was conducted. Results: A total of 1859 subjects were enrolled for the first survey and 16152 for the second. According to the results of the first survey, the median urine iodine concentration was 172.10 µg/L, and the group with adequate or more than adequate iodine accounted for more than 60% of the surveyed population. The prevalence of thyroid disorders was found to be 0.48% for overt hyperthyroidism, 0.43% for subclinical hyperthyroidism, 0.43% for Grave's disease, 1.34% for overt hypothyroidism, 16.62% for subclinical hypothyroidism, 16.73% for positive thyroid antibody, 12.96% for TPOAb positive, 10.06% for TGAb positive, 0.81% for goiter, 14.85% for single nodule, 14.42% for multi-nodules, and 29.26% for thyroid nodules. Excess iodine is a risk factor for subclinical hypothyroidism ( OR=1.50, 95% confidence interval [ CI]: 1.07-2.10, P<0.05), and iodine deficiency is a risk factor for multiple thyroid nodules ( OR=1.45, 95% CI: 1.02-2.05, P<0.05). The total prevalence of hyperthyroidism, hypothyroidism and Hashimoto's thyroiditis in the two surveys was 6.58% and 5.95%, respectively, showing no significant difference. The second survey lacked accurate data on thyroid nodules. Conclusion: The iodine nutritional status of adults in Chengdu in recent years was appropriate. The total prevalence of hyperthyroidism, hypothyroidism and Hashimoto's thyroiditis remained stable, while that of thyroid nodule increased in recent years. We should continue with the implementation of the universal salt iodization policy and reinforce efforts in monitoring. Furthermore, we should make an active effort to look into the etiology of thyroid nodules.

Interpretation of Chinese Society of Endocrinology consensus statement on hyperglycemia management target in adult inpatients in China.

Hyperglycemia of inpatients will increase the incidence of complications, mortality and medical cost, meanwhile prolong the course of hospitalization. A consensus on hyperglycemia management target in adult inpatients is proposed by experts of the Chinese Society of Endocrinology in order to control hyperglycemia of inpatients safely and effectively. Individualization is emphasized in this consensus. Different stratified glycemic targets should be established according to different patients and conditions. Target blood glucose control is unnecessary for diabetic patients during hospital stay. Glycemic decrement should generally not be quick. Hypoglycemia should be avoided as much as possible, and for overweight and obesity individuals, weight gain should be avoided as much as possible also. At the same time, the risks of infection and hyperglycemic crisis must also be avoided due to loose glycemic control.

Activation of PPARδ promotes mitochondrial energy metabolism and decreases basal insulin secretion in palmitate-treated ß-cells.

The peroxisome proliferator-activated receptor δ (PPARδ) regulates the expression of genes involved in cellular lipid and cell energy metabolism in many metabolically active tissues, such as liver, muscle, and fat, and plays a role in the cellular response to stress and environmental stimuli. The particular role of PPARδ in insulin-secreting ß-cells, however, is not well understood; we recently identified the cell-specific role of PPARδ on mitochondrial energy metabolism and insulin secretion in lipotoxic ß-cells. After treatment of HIT-T15 cells, a syrian hamster pancreatic ß-cell line, with high concentrations of palmitate and/or the specific PPARδ agonist GW501516, we detected the gene expression changes for transcripts, such as peroxisome proliferator-activated receptor gamma co-activator 1 (PGC-1α), nuclear respiratory factor 1 (NRF-1), mitochondrial transcription factor A (mtTFA), the protein levels of the mitochondria uncoupling protein 2 (UCP2), mitochondrial morphology, the insulin secretion capacity and ATP/ADP ratio. Our results show that GW501516 treatment promoted generation of mitochondrial ATP, as well as expression levels of PGC-1α, NRF-1 and mtTFA, decreased basal insulin secretion, but had no effect on glucose-stimulated insulin secretion (GSIS), increased amounts of UCP2 and changed ATP-to-ADP ratio, improved mitochondrial morphology in palmitate-treated ß-cells. GW501516-induced activation of PPARδ enhanced mitochondrial energy metabolism, but also promoted a concomitant mitochondrial uncoupling and resulted in decreased basal insulin secretion and restricted GSIS; this observation indicated the possible action of a protective mechanism responding to the alleviation of excessive lipid load and basal insulin secretion in lipotoxic ß-cells.

[Isolation, purification and primary culture of rat pancreatic beta-cells].

OBJECTIVE: To isolate and purify rat pancreatic beta-cells and to explore the best conditions for the primary culture of the pancreatic beta-cells in vitro. METHODS: The pancreas of Norman Wistar rats were digested by collagenase V. The islets were purified by mesh sieve. The activity of the islets was stimulated by different concentrations of glucose and detected by dithizone dye. The purified islets were put into RPMI-1640 nutritive medium for culture overnight. The cultured islets were digested again with trypsin and DNAase to obtain the suspension containing single pancreatic cells. The beta-cells were separated and purified in a fluorescence-activated cell sorter (FACS) in the medium containing 2.8 mmol/L glucose. The purified beta-cells were identified by immunohistochemistry and glucose stimulating test. Ham's F-10 with different concentrations of glucose and 3-Isobutyl-1-methylxanthine (IBMX) were used as nutritive medium for the primary cell culture for 24 hours. The best conditions for the culture were identified. RESULTS: An average of 550 +/- 90 islets with fine activities were obtained per rat. The purification with FACS obtained about 5688 beta-cells per rat, with a recovery rate of (93.69 +/- 1.26)% and a purity of (85.5 +/- 1.24)%. A concentration of 10.0 mmol/L and 16.0 mmol/L glucose in primary culture for 24 hours produced the highest survival rates of beta-cells, but IBMX did not increase the survival rates of beta-cells. CONCLUSION: FACS is effective in purifying pancreatic beta-cells from the suspension with a medium containing 2.8 mmol/L glucose. Pancreatic beta-cells maintain relatively high activities in Ham's F-10 medium containing 10.0-16.0 mmol/L glucose in primary culture.