Sex differences in predictive factors for onset of type 2 diabetes in Japanese individuals: A 15-year follow-up study

Risk factors for chronic kidney disease progression over 20 years for primary prevention in Japanese individuals at a preventive medicine research center: Focus on the influence of plasma glucose levels

AIMS/INTRODUCTION

Chronic kidney disease (CKD) is a very important issue globally because of the risk of its progressing to end-stage renal disease. We aimed to identify factors contributing to long-term estimated glomerular filtration rate (eGFR) decline to determine an early diagnosis and prevent CKD progression.

MATERIALS AND METHODS

From January 2003 to December 2006, 5,507 individuals underwent health checkups at our hospital's Preventive Medicine Research Center. We ultimately enrolled 2,175 individuals. The eGFR was ≥60 mL/min/1.73 m2 at the start of observation period, which was 20 years. The event onset time was the day that the eGFR became <30 mL/min during the 20-year period. Baseline risk factors - in particular, the effect of plasma glucose levels on the eGFR - were extracted and evaluated by using Fine and Gray analysis.

RESULTS

During the 20-year observation, the hazard ratio (HR) of CKD progression was examined. A fasting plasma glucose (FPG) level ≥105 mg/dL was significantly associated with the risk of CKD progressing to an eGFR <30 mL/min. This trend was similar in the slope of eGFR. An FPG ≥105 mg/dL or an glycated hemoglobin level ≥6.5% was useful for intervening in CKD progression. Multivariate analysis showed that independent risk factors were an FPG level ≥105 mg/dL (HR 1.9; P < 0.001), age ≥60 years (HR 3.86; P < 0.001), obesity (HR 1.61; P < 0.01) and urinary protein (HR 1.55; P < 0.01).

CONCLUSIONS

For early intervention against a reduction in the eGFR, detecting mild increases in FPG ≥105 mg/dL in patients with CKD with or without diabetes is useful.

Experimental periodontitis induced hypoadiponectinemia by IRE1α-mediated endoplasmic reticulum stress in adipocytes

BACKGROUD

Hypoadiponectinemia is the important cause of insulin resistance. Recent studies have shown that periodontitis is associated with hypoadiponectinemia. The purpose of this study was to investigate the effect of periodontitis-induced endoplasmic reticulum stress (ERS) in visceral adipocytes on hypoadiponectinemia.

METHODS

Rat periodontitis models were established by local ligation with silk around the bilateral maxillary second molars. Porphyromonas gingivalis-lipopolysaccharid (P.g-LPS) was also used to stimulate the visceral adipocytes in vitro. The protein expression levels of glucose regulated protein 78 (GRP78), inositol-requiring protein 1α (IRE1α), protein kinase RNA-like ER kinase (PERK), activating transcription factor 6 (ATF6) and adiponectin were detected. IRE1α lentiviruses were transfected into visceral adipocytes in vitro, and an IRE1α inhibitor (KIRA6) was injected in epididymal adipose tissue of rats to detect and verify the effect of ERS on adiponectin expression in visceral adipocytes in vivo.

RESULTS

Hypoadiponectinemia was observed in periodontitis rat, and the expression levels of ERS key proteins GRP78 and the phosphorylation levels of IRE1α (p-IRE1α)/IRE1α in visceral adipocytes were increased, while the expression levels of adiponectin protein were decreased. After KIRA6 injection into epididymal adipose tissue of rats with periodontitis, adiponectin levels in visceral adipocytes increased, and serum adiponectin levels recovered to a certain extent. The protein expression levels of GRP78 and p-IRE1α/IRE1α were increased and adiponectin protein expression was decreased in P.g-LPS-induced visceral adipocytes. Overexpression of IRE1α further inhibited adiponectin expression in P.g-LPS-stimulated visceral adipocytes, and conversely, IRE1α inhibition restored adiponectin expression.

CONCLUSIONS

Our findings suggest that periodontitis induces ERS in visceral adipocytes leading to hypoadiponectinemia. IRE1α is a key protein regulating adiponectin expression in visceral adipocytes.

The Role of Adipokines in Inflammatory Mechanisms of Obesity

Adipokines are currently widely studied cellular signaling proteins produced by adipose tissue and involved in various processes, including inflammation; energy and appetite modulation; lipid and glucose metabolism; insulin sensitivity; endothelial cell functioning; angiogenesis; the regulation of blood pressure; and hemostasis. The current review attempted to highlight the key functions of adipokines in the inflammatory mechanisms of obesity, its complications, and its associated diseases. An extensive search for materials on the role of adipokines in the pathogenesis of obesity was conducted online using the PubMed and Scopus databases until October 2022.