Thyroid function, glycemic control, and diabetic nephropathy in patients with type 2 diabetes over 24 months: prospective observational study.

BACKGROUND: The higher prevalence of thyroid dysfunction in type 1 diabetes patients has been well established, whereas it is a matter of debate whether that is also observed in type 2 diabetes patients. This study was conducted to reveal whether higher prevalence of thyroid dysfunction is observed in patients with type 2 diabetes. METHODS: We examined thyroid functions and thyroid autoantibodies in 200 patients with type 2 diabetes and 225 controls, with 24 months follow up for those with type 2 diabetes. RESULTS: Serum free triiodothyronine (fT3) levels and fT3/free thyroxine (fT4) ratio were significantly lower, while fT4 levels were significantly higher in patients with type 2 diabetes. The number of patients with thyroid dysfunction or patients positive for thyroid autoantibodies were not different between the two groups. The fT3/fT4 ratio was positively and negatively correlated with serum c-peptide and HbA1c levels, respectively, suggesting that the difference can be attributable to insulin resistance and diabetic control. In the follow-up observation, we found no significant correlation between basal thyrotropin (TSH), fT3, fT4 or fT3/fT4 ratio with the amounts of changes of HbA1c levels at 12 or 24 months after the basal measurements. There was a negative relationship between TSH levels and eGFR at baseline measurements, but TSH levels did not seem to predict future decline of eGFR levels. No relationship was observed between urine albumin/ g‧cre levels and thyroid function. CONCLUSION: Thyroid dysfunction and thyroid autoantibodies were not different in prevalence between patients with type 2 diabetes and controls, although in patients with type 2 diabetes, the fT3/fT4 ratio was decreased. Basal thyroid function did not predict future diabetes control or renal function within 24 months of follow-up.

Targeting Adaptive IRE1α Signaling and PLK2 in Multiple Myeloma: Possible Anti-Tumor Mechanisms of KIRA8 and Nilotinib.

BACKGROUND: Inositol-requiring enzyme 1α (IRE1α), along with protein kinase R-like endoplasmic reticulum kinase (PERK), is a principal regulator of the unfolded protein response (UPR). Recently, the 'mono'-specific IRE1α inhibitor, kinase-inhibiting RNase attenuator 6 (KIRA6), demonstrated a promising effect against multiple myeloma (MM). Side-stepping the clinical translation, a detailed UPR phenotype in patients with MM and the mechanisms of how KIRA8 works in MM remains unclear. METHODS: We characterized UPR phenotypes in the bone marrow of patients with newly diagnosed MM. Then, in human MM cells we analyzed the possible anti-tumor mechanisms of KIRA8 and a Food and Drug Administration (FDA)-approved drug, nilotinib, which we recently identified as having a strong inhibitory effect against IRE1α activity. Finally, we performed an RNA-sequence analysis to detect key IRE1α-related molecules against MM. RESULTS: We illustrated the dominant induction of adaptive UPR markers under IRE1α over the PERK pathway in patients with MM. In human MM cells, KIRA8 decreased cell viability and induced apoptosis, along with the induction of C/EBP homologous protein (CHOP); its combination with bortezomib exhibited more anti-myeloma effects than KIRA8 alone. Nilotinib exerted a similar effect compared with KIRA8. RNA-sequencing identified Polo-like kinase 2 (PLK2) as a KIRA8-suppressed gene. Specifically, the IRE1α overexpression induced PLK2 expression, which was decreased by KIRA8. KIRA8 and PLK2 inhibition exerted anti-myeloma effects with apoptosis induction and the regulation of cell proliferation. Finally, PLK2 was pathologically confirmed to be highly expressed in patients with MM. CONCLUSION: Dominant activation of adaptive IRE1α was established in patients with MM. Both KIRA8 and nilotinib exhibited anti-myeloma effects, which were enhanced by bortezomib. Adaptive IRE1α signaling and PLK2 could be potential therapeutic targets and biomarkers in MM.

Renoprotective potential of concomittant medications with SGLT2 inhibitors and renin-angiotensin system inhibitors in diabetic nephropathy without albuminuria: a retrospective cohort study.

The renal protective effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors and renin-angiotensin system (RAS) inhibitors on diabetic nephropathy without albuminuria have not been fully investigated. This retrospective cohort study focused on patients with type 2 diabetes mellitus who had a baseline estimated glomerular filtration rate (eGFR) of > 30 mL/min/1.73 m2, and a urinary albumin-to-creatinine ratio < 30 mg/gCr. After propensity score matching, using covariates such as age, body mass index, systolic blood pressure, hemoglobin A1c levels, and prescription history of RAS inhibitors, we established a cohort of 58 patients: the SGLT2 inhibitor group (n = 28) and the control group (n = 28). In this cohort, we compared the annual eGFR decline rate between the two groups. The SGLT2 inhibitor group exhibited a significantly smaller eGFR change than the control group (- 1.15 vs. - 2.18 mL/min/1.73 m2/year). Within the SGLT2 inhibitor group, patients prescribed RAS inhibitors had demonstrated an even smaller eGFR change (- 0.70 mL/min/1.73 m2/year). In conclusion, SGLT2 inhibitors also have safeguarding effects in the stage of diabetic nephropathy without albuminuria, and the combined use of a SGLT2 inhibitor and a RAS inhibitor appears to be more effective than the single use of each.

Reduced Fat Taste Sensitivity in Obese Japanese Patients and Its Recovery after a Short-Term Weight Loss Program.

Fat taste has recently attracted attention as the 'sixth taste.' However, the relationship between fat and sweet taste in Japanese obesity has not yet been examined, and no reports have ascertained whether improvement of fat taste can be obtained by weight loss. Patients were recruited into obesity group (BMI≥30 kg/m2; n=15) or control group (BMI<25 kg/m2; n=11). They answered a questionnaire on smoking, eating behavior, lifestyle, and food frequency, and their taste thresholds were measured (fat, umami, and sweet). The obesity group was tested twice (on admission and before discharge). They showed several eating behavior abnormalities, higher total energy intake, and less physical activity. There were some gender differences: physical inactivity was more prominent in females, and high total energy intake in males, which correlates with fat taste rank. Fat taste rank was significantly higher in obesity group, whereas taste rank of umami and sweet were not significantly different. Gender-specific analysis of fat taste rank revealed only male obesity showed significant difference. Reduced sensitivity of fat may be specific to male gender or obesity by overeating, but not by physical inactivity. Multiple logistic regression analysis revealed that fat taste was a factor relevant to obesity. Fat taste significantly improved after a weight loss program, with average duration of 11.3 d. Japanese obese people, especially males and those who are obese by overeating, have reduced sensitivity to fat taste. This can be recovered by even a short-term weight loss program.

Nicotinic acetylcholine receptor signaling regulates inositol-requiring enzyme 1α activation to protect ß-cells against terminal unfolded protein response under irremediable endoplasmic reticulum stress.

AIMS/INTRODUCTION: Under irremediable endoplasmic reticulum (ER) stress, hyperactivated inositol-requiring enzyme 1α (IRE1α) triggers the terminal unfolded protein response (T-UPR), causing crucial cell dysfunction and apoptosis. We hypothesized that nicotinic acetylcholine receptor (nAChR) signaling regulates IRE1α activation to protect ß-cells from the T-UPR under ER stress. MATERIALS AND METHODS: The effects of nicotine on IRE1α activation and key T-UPR markers, thioredoxin-interacting protein and insulin/proinsulin, were analyzed by real-time polymerase chain reaction and western blotting in rat INS-1 and human EndoC-ßH1 ß-cell lines. Doxycycline-inducible IRE1α overexpression or ER stress agents were used to induce IRE1α activation. An α7 subunit-specific nAChR agonist (PNU-282987) and small interfering ribonucleic acid for α7 subunit-specific nAChR were used to modulate nAChR signaling. RESULTS: Nicotine inhibits the increase in thioredoxin-interacting protein and the decrease in insulin 1/proinsulin expression levels induced by either forced IRE1α hyperactivation or ER stress agents. Nicotine attenuated X-box-binding protein-1 messenger ribonucleic acid site-specific splicing and IRE1α autophosphorylation induced by ER stress. Furthermore, PNU-282987 attenuated T-UPR induction by either forced IRE1α activation or ER stress agents. The effects of nicotine on attenuating thioredoxin-interacting protein and preserving insulin 1 expression levels were attenuated by pharmacological and genetic inhibition of α7 nAChR. Finally, nicotine suppressed apoptosis induced by either forced IRE1α activation or ER stress agents. CONCLUSIONS: Our findings suggest that nAChR signaling regulates IRE1α activation to protect ß-cells from the T-UPR and apoptosis under ER stress partly through α7 nAChR. Targeting nAChR signaling to inhibit the T-UPR cascade may therefore hold therapeutic promise by thwarting ß-cell death in diabetes.

Myotonic dystrophy type 1 with diabetes mellitus, mixed hypogonadism and adrenal insufficiency.

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystem disease affecting muscles, the eyes and the endocrine organs. Diabetes mellitus and primary hypogonadism are endocrine manifestations typically seen in patients with DM1. Abnormalities of hypothalamic-pituitary-adrenal (HPA) axis have also been reported in some DM1 patients. We present a case of DM1 with a rare combination of multiple endocrinopathies; diabetes mellitus, a combined form of primary and secondary hypogonadism, and dysfunction of the HPA axis. In the present case, diabetes mellitus was characterized by severe insulin resistance with hyperinsulinemia. Glycemic control improved after modification of insulin sensitizers, such as metformin and pioglitazone. Hypogonadism was treated with testosterone replacement therapy. Notably, body composition analysis revealed increase in muscle mass and decrease in fat mass in our patient. This implies that manifestations of hypogonadism could be hidden by symptoms of myotonic dystrophy. Our patient had no symptoms associated with adrenal deficiency, so adrenal dysfunction was carefully followed up without hydrocortisone replacement therapy. In this report, we highlight the necessity for evaluation and treatment of multiple endocrinopathies in patients with DM1. LEARNING POINTS: DM1 patients could be affected by a variety of multiple endocrinopathies.Our patients with DM1 presented rare combinations of multiple endocrinopathies; diabetes mellitus, combined form of primary and secondary hypogonadism and dysfunction of HPA axis.Testosterone treatment of hypogonadism in patients with DM1 could improve body composition.The patients with DM1 should be assessed endocrine functions and treated depending on the degree of each endocrine dysfunction.