No abstract

Serum concentrations of environmental pollutants have been positively correlated with diabetes and metabolic syndrome in epidemiologic studies. In turn, abnormal mitochondrial function has been associated with the diseases. The relationships between these variables, however, have not been studied. We developed novel cell-based aryl hydrocarbon receptor (AhR) agonist bioassay system without solvent extraction process and analyzed whether low-dose circulating AhR ligands in human serum are associated with parameters of metabolic syndrome and mitochondrial function. Serum AhR ligand activities were measured as serum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (sTCDDeq) in pM using 10 μL human sera from 97 Korean participants (47 with glucose intolerance and 50 matched controls, average age of 46.6 ± 9.9 years, 53 male and 45 female). sTCDDeq were higher in participants with glucose intolerance than normal controls and were positively associated (P < 0.01) with obesity, blood pressure, serum triglyceride, and fasting glucose, but not with HDL-cholesterol. Body mass index was in a positive linear relationship with serum AhR ligands in healthy participants. When myoblast cells were incubated with human sera, ATP generating power of mitochondria became impaired in an AhR ligand concentration-dependent manner. Our results support that circulating AhR ligands may directly reduce mitochondrial function in tissues, leading to weight gain, glucose intolerance, and metabolic syndrome. Our rapid cell-based assay using minute volume of human serum may provide one of the best monitoring systems for circulating AhR ligands, good clinical biomarkers for the progress of disease and therapeutic efficacy.

This work was supported in part by the grant from the Korea Centers for Disease Control and Prevention (2009-E00591-00). The work was also supported by the Ewha Global Top5 Grant 2013 of Ewha Womans University. None of the authors has any conflict of interest to declare.

We investigated the prevalence and risk factors of vertebral fractures in Korea. In a community-based prospective epidemiology study, 1,155 men and 1,529 women (mean age 59 years, range 43-74) were recruited from Ansung, a rural Korean community. Prevalent vertebral fractures were identified on the lateral spinal radiographs at T11 to L4 using vertebral morphometry. Bone mineral density (BMD) was measured at the lumbar spine, femur neck and total hip. Of the 2,684 subjects, 137 (11.9%) men and 227 (14.8%) women had vertebral fractures and the standardized prevalence for vertebral fractures using the age distribution of Korean population was 8.8% in men and 12.6% in women. In univariate analysis, older age, low hip circumference, low BMD, low income and education levels in both sexes, previous history of fracture in men, high waist-to-hip circumference ratio, postmenopausal status, longer duration since menopause, and higher number of pregnancies and deliveries in women were associated with an increased risk of vertebral fractures. However, after adjusting for age, only low BMD in both sexes and a previous history of fracture in men were significantly associated with an increased risk of vertebral fractures. Vertebral fractures are prevalent in Korea as in other countries. Older age, low BMD and a previous history of fracture are significant risk factors for vertebral fractures.

BackgroundThere are no published data regarding fracture risk in type 2 diabetic patients in Korea. In this study, we compared the fracture incidence and risk of osteoporosis of type 2 diabetic female patients with those in a non-diabetic hypertensive cohort.MethodsThe incidence of fracture in a type 2 diabetic cohort was compared with that in a non-diabetic hypertensive cohort over the course of 7 years. Female type 2 diabetic and non-diabetic hypertensive patients who visited Eulji General Hospital outpatient clinic from January 2004 to April 2004 were assigned to the diabetic cohort and the non-diabetic hypertensive cohort, respectively. Surveys on fracture event, use of anti-osteoporosis medications, and bone mineral density were performed.ResultsThe number of fractures was 88 in the female diabetic cohort (n=1,268, 60.6±11.5 years) and 57 in the female non-diabetic hypertensive cohort (n=1,014, 61.4±11.7 years). The RR in the diabetic cohort was 1.38 (P=0.064; 95% confidence interval [CI], 0.98 to 1.94) when adjusted for age. Diabetic patients with microvascular complications (61.0%) showed a higher RR of 1.81 (P=0.014; 95% CI, 1.13 to 2.92) compared with those without these complications. The prevalence of osteoporosis was comparable between the groups, while use of anti-osteoporosis medication was more common in the diabetic cohort (12.8%) than in the hypertensive cohort (4.5%) (P<0.001).ConclusionIn our study, a higher fracture risk was observed in female type 2 diabetics with microvascular complications. Special concern for this risk group is warranted.