Tetsuji Niiya

Nocturia and prevalence of erectile dysfunction in Japanese patients with type 2 diabetes mellitus: The Dogo Study

Several epidemiological studies have reported a positive association between nocturia and erectile dysfunction (ED). Yet only limited evidence exists regarding the association between nocturia and ED among patients with type 2 diabetes mellitus, although nocturia and ED are common among type 2 diabetes mellitus patients.

Serum lipoprotein(a) levels and diabetic nephropathy among Japanese patients with type 2 diabetes mellitus

AIMS We aimed to evaluate the association between serum lipoprotein(a) [Lp(a)] levels and diabetic nephropathy among Japanese patients with type 2 diabetes mellitus. METHODS This study included 581 patients with type 2 diabetes mellitus. Serum Lp(a) levels were divided into four groups; the cut-off points were at the 30th, 60th, and 90th percentile values on the basis of the distribution for all subjects. Diabetic nephropathy was defined as present when the urinary albumin-creatinine ratio was ≥33.9mg/mmol creatinine and/or the estimated glomerular filtration rate was <30ml/min/1.72m(2). Adjustment was made for age, sex, body mass index, hemoglobin A1c, duration of diabetes mellitus, current drinking, current smoking, hypertension, dyslipidemia, coronary heart disease, and stroke. RESULTS Higher serum Lp(a) levels were significantly associated with a higher prevalence of diabetic nephropathy: the adjusted odds ratios (95% confidence intervals) for diabetic nephropathy in relation to serum Lp(a) levels of ≤6, 7-15, 16-38, and ≥39mg/dl were 1.00 (reference), 2.74 (1.08-7.00), 3.31 (1.28-8.54), and 4.80 (1.57-14.60), respectively (P for trend=0.004). CONCLUSIONS The results suggest that serum Lp(a) levels may be positively associated with diabetic nephropathy among Japanese patients with type 2 diabetes mellitus.

Clinical usefulness of quantitative evaluation of visceral fat by ultrasonography.

PurposeThe aim of this work was to evaluate the usefulness of a proposed method for visceral fat volume assessment by ultrasonography (US) in identifying those at risk of metabolic syndrome, and also to establish the most suitable cutoff level of waist circumference for the diagnosis of visceral adiposity.MethodsOne hundred and fifty-two outpatients with metabolic diseases such as hypertension, diabetes, or dyslipidemia were studied. The total visceral fat volume (total-VFA) was measured by computed tomography (CT), the visceral fat area at the level of the umbilicus was measured by CT (CT-VFA), and the visceral fat area was also measured by US (US-VFA), as we recently proposed.ResultsSignificant correlation coefficients were found between total-VFA and CT-VFA, US-VFA, and waist circumference in men but not in women. The correlation co-efficient between US-VFA and waist circumference was significantly positive in men and weakly positive in women. According to receiver–operator characteristic curves, the cutoff value of waist circumference yielding the maximal sensitivity plus specificity for predicting more than 100 cm2 of US-VFA was 85 cm in men and 84 cm in women. The change in US-VFA was significantly larger than that in waist circumference after a 6-month interval.ConclusionThe US-measured visceral fat area is more useful than waist circumference in a clinical setting.

Physical activity and prevalence of erectile dysfunction in Japanese patients with type 2 diabetes mellitus: The Dogo Study

To date, there is no evidence regarding the association between physical activity (PA) and erectile dysfunction (ED) among Japanese patients with type 2 diabetes mellitus. We investigated this issue among Japanese patients with type 2 diabetes mellitus.

Self-reported sitting time and prevalence of erectile dysfunction in Japanese patients with type 2 diabetes mellitus: The Dogo Study

AIMS No evidence exists regarding the association between sitting time and erectile dysfunction (ED) among patients with type 2 diabetes mellitus. The aim of this study was to evaluate the association between self-reported sitting time and ED among patients with type 2 diabetes mellitus. METHODS Study subjects were 430 male Japanese patients with type 2 diabetes mellitus (mean age, 60.5years). A self-administered questionnaire was used to collect information on the variables under study. The study subjects were asked about time spent sitting during typical 24-hour periods over the past 12months. Subjects were divided into four groups according to self-reported sitting time: 1) <5hours, 2) 5-7hours, 3) 7-9hours, and 4) ≥9hours. ED was defined as present when a subject had a Sexual Health Inventory for Men score <8. Adjustment was made for age, body mass index, duration of type 2 diabetes, current smoking, current drinking, hypertension, coronary artery disease, stroke, glycated hemoglobin, walking habit, and diabetic neuropathy. RESULTS The prevalence values of moderate to severe ED and severe ED were 36.1% and 49.8%. At least 9hours sitting was independently positively associated with severe ED but not moderate to severe ED; the adjusted OR was 1.84 (95% CI: 1.06-3.33). In the multivariate model, there was a statistically significant inverse exposure-response relationship between the self-reported sitting time and severe ED (p for trend=0.029). CONCLUSIONS Self-reported sitting time may be positively associated with ED in Japanese patients with type 2 diabetes mellitus.

Relationship between urine pH and abnormal glucose tolerance in a community-based study

The association between urine pH and abnormal glucose tolerance in men and women is unclear; therefore, we carried out a community‐based, cross‐sectional study to investigate sex‐specific associations between these values, possible indicators of prediabetes and type 2 diabetes.

Macrovascular Complications and Prevalence of Urgency Incontinence in Japanese Patients with Type 2 Diabetes Mellitus: The Dogo Study

Objective Macrovascular diseases and urgency incontinence are common among Japanese patients with type 2 diabetes mellitus. However, little evidence exists regarding the association between stroke and urgency incontinence among patients with type 2 diabetes mellitus. We examined the associations between macrovascular complications and urgency incontinence among Japanese patients with type 2 diabetes mellitus. Methods The study subjects were 818 Japanese patients with type 2 diabetes mellitus. Urgency incontinence was defined as present when a subject answered “once a week or more” to the question: “Within one week, how often do you leak urine because you cannot defer the sudden desire to urinate?” We adjusted our analyses for sex, age, body mass index, duration of type 2 diabetes, current smoking, current drinking, hypertension, dyslipidemia, glycated hemoglobin, diabetic nephropathy, diabetic retinopathy, and diabetic peripheral neuropathy. Results The prevalence of urgency incontinence was 9.2%. Stroke was independently positively associated with urgency incontinence, with an adjusted odds ratio of 2.34 (95% confidence interval: 1.03-4.95). The associations between ischemic heart disease or peripheral artery disease and the prevalence of urgency incontinence were not significant. Conclusion In Japanese patients with type 2 diabetes mellitus, stroke, but not ischemic heart diseases or peripheral artery disease, was independently positively associated with urgency incontinence.

Obesity and the prevalence of nocturia in Japanese elderly patients with type 2 diabetes mellitus: The Dogo study

Nocturia is common among patients with type 2 diabetes mellitus, but limited evidence regarding the association between body mass index (BMI) and nocturia exists among such patients. The aim of the present study, therefore, was to evaluate the association between BMI and nocturia among Japanese patients with type 2 diabetes mellitus.

Free testosterone concentration is inversely associated with markers of liver fibrosis in men with type 2 diabetes mellitus

The association between serum testosterone level and liver fibrosis in patients with non-alcoholic fatty liver disease is unclear. To clarify this association, we investigated the relationship between serum free testosterone concentration and markers of liver fibrosis in men with type 2 diabetes mellitus but no obvious features of alcohol consumption. This retrospective observational cross-sectional study enrolled 248 men with type 2 diabetes mellitus. The FIB-4 index was measured as a marker of liver fibrosis, and multiple linear regression analysis was performed to examine its association with serum free testosterone concentration. In addition, the 7S domain of type IV collagen (IV-7S) was examined in 140 of the 248 patients. The mean free testosterone concentration was 10.6 ± 6.8 pg/mL and the means of the FIB-4 index and IV-7S were 1.64 ± 1.19 and 4.02 ± 1.11 ng/mL, respectively. After adjusting for all relevant variables, serum free testosterone concentrations were inversely associated with both the FIB-4 index and IV-7S (β; -0.28, P < 0.0001, and β; -0.28, P = 0.002, respectively). Measuring serum free testosterone concentrations in men with type 2 diabetes mellitus may help to predict progression to advanced liver disease. Identifying patients at risk may help to prevent the development of cirrhosis and hepatocellular carcinoma.

B-type natriuretic peptide and renal function in Japanese patients with type 2 diabetes mellitus: The Dogo Study

Among patients with type 2 diabetes mellitus, the association between B-type natriuretic peptide (BNP) and renal function remains controversial. We therefore investigated this issue among Japanese patients with type 2 diabetes mellitus. This study included 687 Japanese patients with type 2 diabetes mellitus. BNP levels were divided at quartile points on the basis of the distribution. We used four outcomes regarding the renal function: 1) chronic kidney disease (CKD): estimated glomerular filtration rate (eGFR) < 60ml/min/1.72m2, 2) advanced CKD: eGFR < 30ml/min/1.72m2, 3) microalbuminuria: urinary albumin creatinine ratio (UACR) ≥ 30 mg/g creatinine, and 4) macroalbuminuria: UACR ≥ 300 mg/g creatinine. The prevalence values of CKD, advanced CKD, microalbuminuria, and macroalbuminuria were 27.4％, 2.5%, 31.4%, and 9.3%, respectively. Highest BNP (≥ 39.2 ng/ml) was independently positively associated with microalbuminuria and macroalbuminuria (adjusted ORs, 2.61 [95% CI: 1.53-4.49] and 3.45 [95% CI: 1.46-8.72], respectively). High BNP was not associated with advanced CKD or CKD. There was a statistically significant positive exposure-response relationships between the BNP level and advanced CKD, microalbuminuria, and macroalbuminuria (p for trend = 0.047, 0.001, and 0.003, respectively). BNP level may be independently positively associated with advanced CKD, microalbuminuria, and macroalbuminuria but not CKD in Japanese patients with type 2 diabetes mellitus.