HOMA-IR Values are Associated With Glycemic Control in Japanese Subjects Without Diabetes or Obesity: The KOBE Study

Changes in glucose metabolism, C-reactive protein, and liver enzymes following intake of NAD + precursor supplementation: a systematic review and meta-regression analysis

BACKGROUND

There are contradictory effects regarding the effect of NAD + precursor on glucose metabolism and liver enzymes. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of NAD + precursor supplementation on glucose metabolism, C-reactive protein (CRP), and liver enzymes.

METHODS

PubMed/MEDLINE, Web of Science, SCOPUS, and Embase databases were searched using standard keywords to identify all controlled trials investigating the glucose metabolism, CRP, and liver enzymes effects of NAD + precursor. Pooled weighted mean difference (WMD) and 95% confidence intervals (95% CI) were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

Forty-five articles with 9256 participants' were included in this article. The pooled findings showed that NAD + precursor supplementation had a significant increase in glucose (WMD: 2.17 mg/dL, 95% CI: 0.68, 3.66, P = 0.004) and HbA1c (WMD: 0.11, 95% CI: 0.06, 0.16, P < 0.001) as well as a significant decrease in CRP (WMD: -0.93 mg/l, 95% CI -1.47 to -0.40, P < 0.001) compared with control group, and was not statistically significant with respect to insulin and homeostasis model assessment of insulin resistance (HOMA-IR). However, we found no systemic changes in aspartate transaminase (AST), alanine transaminase (ALT), or alkaline phosphatase (ALP) levels after NAD + precursor supplementation. The results of the subgroup analysis showed that the intake of NAD + precursor during the intervention of more than 12 weeks caused a greater increase in the glucose level. Furthermore, Nicotinic acid supplementation (NA) causes a greater increase in glucose and HbA1c levels than nicotinamide (NE) supplementation.

CONCLUSIONS

Overall, these findings suggest that NAD + precursor supplementation might have an increase effect on glucose metabolism as well as a decrease in CRP.

[Correlation between insulin resistance and coronary collateral circulation in patients with chronic total coronary occlusion]

OBJECTIVE

To explore the impact of diabetes on collateral circulation (CC) development in patients with chronic total coronary occlusion (CTO) and the underlying regulatory mechanism.

METHODS

This study was conducted among 87 patients with coronary heart disease (CHD), who had CTO in at least one vessel as confirmed by coronary angiography. Among them 42 patients were found to have a low CC level (Cohen-Rentrop grades 0-1) and 45 had a high CC level (grades 2-3). In the 39 patients with comorbid diabetes mellitus and 48 non-diabetic patients, insulin resistance (IR) levels were compared between the subgroups with different CC levels. The steady-state mode evaluation method was employed for calculating the homeostatic model assessment for insulin resistance index (HOMA-IR) using a mathematical model. During the interventional procedures, collateral and peripheral blood samples were collected from 22 patients for comparison of the metabolites using non-targeted metabolomics analysis.

RESULTS

NT-proBNP levels and LVEF differed significantly between the patients with different CC levels (P<0.05). In non-diabetic patients, HOMA-IR was higher in low CC level group than in high CC level groups. Compared with the non-diabetic patients, the diabetic patients showed 63 upregulated and 48 downregulated metabolites in the collateral blood and 23 upregulated and 14 downregulated metabolites in the peripheral blood. The differential metabolites in the collateral blood were involved in aromatic compound degradation, fatty acid biosynthesis, and steroid degradation pathways; those in the peripheral blood were related with pentose phosphate metabolism, bacterial chemotaxis, hexanoyl-CoA degradation, glycerophospholipid metabolism, and lysine degradation pathways.

CONCLUSION

The non-diabetic patients with a low level of CC had significant insulin resistance. The degradation pathways of aromatic compounds, fatty acid biosynthesis, and steroid degradation are closely correlated with the development of CC.

Seasonal variation in vascular dehydration risk: insights from the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) study

BACKGROUND

Dehydration, a risk factor for ischemic cerebrovascular diseases, is common in summer; however, the incidence of ischemic diseases is not necessarily higher in summer. Therefore, this study aimed to clarify the relationships between serum osmolarity, hematocrit, daily non-alcohol drink (NAD) intake and factors such as season and age as risk factors for dehydration.

METHOD

Participants (703 women and 306 men) in the follow-up survey, in 2012 and 2013, of the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) Study, consisting of healthy individuals living in Kobe, Japan, were categorized into two groups based on the examination month: the warmer and colder seasons. Multivariate analyses were conducted to examine disparities in serum osmolarity, hematocrit, and NAD intake between these two groups.

RESULTS

The colder season was found to be negatively correlated with serum osmolarity and NAD intake, but positively correlated with hematocrit, even after adjusting for relevant factors. Age was independently associated with serum osmolarity, but not with hematocrit and NAD intake.

CONCLUSIONS

This study suggests that intra-vascular volume depletion is more likely in the colder season despite lower serum osmolarity compared to the warmer season. Age-related increases in serum osmolarity without a corresponding rise in water intake may contribute to this. These findings support the importance of addressing dehydration in the colder season, particularly in older adults.

Associations of the baseline level and change in glycosylated hemoglobin A1c with incident hypertension in non-diabetic individuals: a 3-year cohort study

BACKGROUND

Diabetes mellitus increases the risk of developing hypertension. The relationship between glycosylated hemoglobin A1c (HbA1c) level and incident hypertension remains controversial. This study examined the associations of the baseline level and change in the HbA1c level over 3 years with incident hypertension in non-diabetic individuals.

METHODS

This community-based cohort study was conducted with 2591 individuals aged 40-75 years without hypertension or diabetes at baseline, who participated in a longitudinal (REACTION) study program. Questionnaires were administered during interviews, and anthropometric and laboratory measurements were performed at baseline (2011) and follow-up (2014-2015). Multivariate logistic regression models were applied to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of incident hypertension.

RESULTS

Over a median follow-up period of 3.08 years (interquartile range 3.00, 3.25), 384 (14.82%) subjects developed hypertension. In the fully adjusted linear regression models, change in HbA1c remained significantly associated with changes in systolic blood pressure and diastolic blood pressure [β-coefficient (95% CI), 4.421 (2.811-6.032), 1.681 (0.695-2.667)]. Logistic regression analyses showed that baseline HbA1c level was positively associated with incident hypertension in the unadjusted model; however, the association was no longer significant after further adjustment. Change in HbA1c was positively associated with the development of hypertension, both as a categorical variable stratified by tertiles [adjusted OR (95% CI) in the highest tertile was 1.690 (1.240-2.303) versus the lowest tertile)] and as a continuous variable [adjusted OR (95% CI), 1.242 (1.106-1.394)], independent of age, sex, body mass index, systolic blood pressure, fasting plasma glucose level, lipid profile, the HbA1c level at baseline and 3-year change in body mass index.

CONCLUSIONS

A higher baseline HbA1c level was not an independent risk factor for incident hypertension, whereas the change in HbA1c was independently associated with a greater longitudinal increase in blood pressure and an increased risk of incident hypertension in non-diabetic individuals.

Physique at Birth and Cardiovascular Disease Risk Factors in Japanese Urban Residents: the KOBE Study

Aim: This study investigated the relationship between birth physique and cardiovascular risk factors in Japanese urban residents aged 40 years and more.

Methods: A self-administered questionnaire on birth physique was performed among 624 individuals (165 men and 459 women) who participated in the KOBE study. We examined whether self-reported birth physique and available recorded birth weights matched for 72 participants. Then the association between birth physique and risk factors for all participants was examined by gender. Body size at birth in the questionnaire (large, medium, small) was set as an exposure and laboratory values from the baseline survey (2010-2011) were used as outcomes.

Results: Mean (standard deviation) recorded birth weight of 72 participants was 3665 (318), 3051 (300), and 2653 (199) g, in the large, medium, and small group, respectively. In the analysis for all participants, odds ratio for having both hypertension and impaired glucose tolerance were significantly higher in the small versus large birth weight group, which was 7.42 (95% CI 1.75–31.50) for men and 4.44 (95% CI 1.14–17.30) for women after adjusting for age, body mass index, smoking/alcohol/exercise habits, and menstrual status in women. Similar results were observed in participants with recorded birth weight.

Conclusions: The present study indicates that individuals with small physique at birth might be at higher risk for hypertension and impaired glucose tolerance in middle age compared to those with large birth weight.

Association Between Clinical Biomarkers and Optical Coherence Tomography Angiography Parameters in Type 2 Diabetes Mellitus

Purpose

To investigate the clinical significance of the changes in the macular microvasculature in patients with diabetes mellitus type 2 without diabetic retinopathy.

Methods

Fifty-five patients with diabetes mellitus type 2 without diabetic retinopathy and 48 healthy individuals were enrolled in a prospective cross-sectional study. We identified the changes of optical coherence tomography angiography parameters (foveal avascular zone [FAZ] area and circularity, vessel density, and perfusion index) of the 6 × 6-mm macular scan. Correlation and multiple regression analyses were performed between optical coherence tomography angiography parameters and previously known diabetes mellitus type 2-related demographic and systemic characteristics, and serum biochemical markers.

Results

FAZ parameters and perfusion index of the superficial and deep vascular plexus showed significant correlation with serum insulin level, and homeostasis model assessment indices. In multiple linear regression analysis, low insulin levels predicted increased FAZ areas in both the superficial (β = –0.007; P = 0.030) and deep layers (β = –0.010; P = 0.018) and a decreased perfusion index in the deep layer (β = 0.003; P = 0.001).

Conclusions

The expansion and loss of circularity of the FAZ and the decrease in the perfusion index may be affected by insulin resistance and secretory capacity in patients with diabetes mellitus type 2 with no diabetic retinopathy.

Being Conscious of Water Intake Positively Associated with Sufficient Non-Alcohol Drink Intake Regardless of Seasons and Reasons in Healthy Japanese; the KOBE Study: A Cross Sectional Study

The present study sought to clarify if being conscious of water intake (CWI) is associated with sufficient non-alcohol drink (NAD) intake. We used data of healthy participants without diabetes, aged 40–74 years, in the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) study. The association between being CWI and NAD intake was evaluated by multivariate linear regression analyses after adjusting for age, sex, surveyed months (seasons), alcohol drinking, health-awareness life habits, socioeconomic factors, serum osmolarity, estimated daily salt intake, and reasons for NAD intake. Among 988 (698 women and 290 men) participants eligible for the present analyses, 644 participants (65.2%) were CWI and 344 participants (34.8%) were not CWI (non-CWI). The most popular reason for being CWI was to avoid heat stroke in summer and to prevent ischemic cerebral stroke in winter. The CWI group took more NAD, especially decaffeinated beverages, than the non-CWI group (1846.7 ± 675.1 mL/day vs. 1478.0 ± 636.3 ml/day, p < 0.001). There was a significant association between being CWI and NAD intake in multivariate linear regression analyses ever after adjusting for the relevant variables (β = 318.1, p < 0.001). These findings demonstrated CWI, regardless of the reasons and the seasons, was associated with high NAD intake in Japanese healthy population.

HOMA-IR: An independent predictor of advanced liver fibrosis in nondiabetic non-alcoholic fatty liver disease

BACKGROUND AND AIM

Although non-alcoholic fatty liver disease (NAFLD) is common in the general population, identifying patients with advanced fibrosis remains a challenge. We investigated whether the homeostasis model assessment parameter of insulin resistance (HOMA-IR), an index of IR and one of the most important metabolic factors, is an independent predictive factor for advanced fibrosis in nondiabetic patients with NAFLD.

METHODS

This was a retrospective, cross-sectional multicenter study. We included 361 patients with biopsy-proven NAFLD who had not been diagnosed with type 2 diabetes mellitus: 175 (48%) were women and 48 (13%) had advanced fibrosis. We used simple random sampling; the sampling ratio of the estimation and validation groups was 7:3. A logistic model was constructed for both the estimation and validation groups. The explanatory variables were age ≥ 49 years, sex (women), body mass index ≥ 26.7 kg/m² , the presence of hypertension, presence of dyslipidemia, fasting plasma glucose level ≥ 98 mg/dL, fasting immune reactive insulin level ≥ 12.0 μU/mL, and HOMA-IR ≥ 2.90. The median HOMA-IR of the patients was 2.88 (interquartile range: 2.1-4.8).

RESULTS

In the estimation group, univariate and multivariate analyses showed that age, dyslipidemia, and HOMA-IR were independent predictors of advanced fibrosis. In the validation group, only age and HOMA-IR were found to be independent predictors of advanced fibrosis.

CONCLUSIONS

Homeostasis model assessment parameter of insulin resistance was an independent predictor of advanced liver fibrosis in nondiabetic patients with NAFLD. Given that most patients with NAFLD are nondiabetic, it is important to set goals with respect to improving IR to subsequently reduce liver fibrosis.

Higher serum uric acid level is inversely associated with renal function assessed by cystatin C in a Japanese general population without chronic kidney disease: the KOBE study

Background

Although several epidemiological studies have suggested that high serum uric acid (SUA) levels are related to a decline in kidney function, only a few studies have investigated using cystatin C to calculate estimated glomerular filtration rate (eGFR). We aimed to clarify the relationship between SUA levels and kidney function assessed by cystatin C in a Japanese general community population without chronic kidney disease (CKD).

Methods

We conducted a community-based cross-sectional study that included 1086 healthy participants, aged 40–74 years, without CKD and not undergoing treatment of hyperuricemia, who had participated in the baseline survey of the Kobe Orthopedic and Biomedical Epidemiological (KOBE) study. The preconditions for participation in this study were no past histories of cardiovascular disease or cancer, and not undergoing treatment for diabetes, hypertension, or dyslipidemia. We classified the participants into quartiles stratified by sex according to their SUA level and then examined the relationship with eGFR. The odds ratios for having a low eGFR, defined as the lowest quartile of eGFR (i.e., ≤78.4 mL/min/1. 73m²) was estimated according to SUA quartiles (men, Q1 ≤ 5.0, Q2 5.1–5.9, Q3 6.0–6.6, and Q4 ≥ 6.7; women, Q1 ≤ 3.8, Q2 3.9–4.3, Q3 4.4–4.9, and Q4 ≥ 5.0 mg/dL) after adjustment for age, body mass index, systolic blood pressure, HbA1c, high and low density lipoprotein cholesterol, and smoking and drinking habits. The adjusted mean of each quartile was also calculated.

Results

Multivariable-adjusted means of eGFR showed a graded decrease in higher SUA quartiles (men, Q1 90.5, Q2 88.0, Q3 83.5, and Q4 82.0; women, Q1 95.7, Q2 91.3, Q3 89.2, and Q4 86.7). In addition, the multivariable-adjusted odds ratios for having a lower eGFR (95% confidence interval) for each SUA quartile compared with Q1 was Q2 2.29 (0.98, 5.35), Q3 4.94 (2.04, 11.97), and Q4 8.01 (3.20, 20.04) for men, and was Q2 2.20 (1.12, 4.32), Q3 2.68 (1.39, 5.20), and Q4 4.96 (2.62, 9.41) for women.

Conclusions

There was a graded inverse relationship between mild elevations in SUA levels and eGFR assessed by cystatin C in an apparently healthy Japanese population without CKD. This association was similar in both men and women.

Underweight Young Women Without Later Weight Gain Are at High Risk for Osteopenia After Midlife: The KOBE Study

Background

Although underweight young women are targets for interventions to prevent low bone mineral density (BMD), the relationship between change in body mass index (BMI) from youth to older age and BMD has not been widely investigated in community dwellers.

Methods

In 749 healthy Japanese women aged 40–74 years, BMD was measured by quantitative ultrasound and anthropometric measurements, and BMI was calculated from body weight and height. The BMI of participants at age 20 years was estimated by self-reported body weight and their present height. They were classified into four groups according to the presence of underweight (BMI <18.5 kg/m²) at 20 and/or at present. Logistic regression models were used to estimate multivariate-adjusted odds ratios (ORs) of the presence of underweight at 20 and/or at present for osteopenia (BMD T score <−1 standard deviations) compared with participants with BMI ≥18.5 kg/m² both at 20 and at present.

Results

The participants who were underweight both at 20 and at present had a higher OR for osteopenia compared with those with BMI ≥18.5 kg/m² at 20 and at present (OR 3.94; 95% confidence interval [CI], 1.97–7.89). Those underweight only at present also had significantly increased OR of developing osteopenia (OR 2.95; 95% CI, 1.67–5.24). The OR of those underweight only at 20 was 0.87 (95% CI, 0.51–1.48).

Conclusions

Current underweight was associated with increased risk for osteopenia among Japanese women, especially in those who were underweight both at 20 and at present. To prevent low BMD in the future, maintaining appropriate body weight might be effective for young underweight women.