Akihiro Obora

Weight gain since age of 20 as risk of metabolic syndrome even in non-overweight individuals

PurposeMetabolic syndrome (MetS), regardless of the presence of obesity, is known as a risk of diabetes and cardiovascular disease. Weight gain after age 20 reported to be associated with these diseases. Impact of the difference between the body mass index (BMI) at examination and BMI at age 20 (ΔBMIexa−20y) on MetS, especially in non-overweight individuals, remains to be elucidated.MethodsWe analyzed the data of 24,363 individuals (14,301 men and 10,062 women) in this cross-sectional study. The diagnosis of MetS was diagnosed when three or more of the following criteria were present: hypertension, hyperglycemia, hypertriglyceridemia, low HDL-cholesterol level, and abdominal obesity. Logistic regression was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for age, alcohol, smoking, exercise, and BMI at examination.ResultsCompared to the lowest ΔBMIexa−20y tertile (ΔBMIexa−20y < 1.2 kg/m2 in men and ≤0 kg/m2 in women), the highest tertile (ΔBMIexa−20y ≥ 3.2 kg/m2 in men and ≥2.0 kg/m2 in women) was associated with the risk of the presence of MetS (multivariate OR = 1.80, 95%CI 1.53–2.11, p < 0.001 in men and OR = 3.27, 95%CI 2.22–4.96, p < 0.001 in women). This result was also applicable in non-overweight individuals (multivariate OR = 2.06, 95%CI 1.46–2.92, p < 0.001 in men and OR = 2.49, 95%CI 1.40–4.64, p < 0.001 in women).ConclusionsOur analyses showed that ΔBMIexa−20y is associated with the risk of the presence of MetS, even in non-overweight individuals. It is thus important to check weight changes from early adulthood, even in non-overweight individuals.

Ectopic fat obesity presents the greatest risk for incident type 2 diabetes: a population-based longitudinal study

ObjectivesObesity is a risk factor for type 2 diabetes mellitus. Among obesity, visceral fat obesity, and ectopic fat obesity, it has been unclear which has the greatest effect on incident diabetes.MethodsIn this historical cohort study of 8430 men and 7034 women, we investigated the effect of obesity phenotypes on incident diabetes. Obesity, visceral fat obesity, and ectopic fat obesity were defined as body mass index ≥25 kg/m2, waist circumference ≥90 cm in men or ≥80 cm in women, and having fatty liver diagnosed by abdominal ultrasonography, respectively. We divided the participants into eight groups according to the presence or absence of the three obesity phenotypes.ResultsDuring the median 5.8 years follow-up for men and 5.1 years follow-up for women, 286 men and 87 women developed diabetes. Compared to the non-obese group, the hazard ratios (HRs) of incident diabetes in the only-obesity, only-visceral fat obesity, only-ectopic fat obesity groups, and with all-three types of obesity group were 1.85 (95%CI 1.06–3.26, p = 0.05) in men and 1.79 (0.24–13.21, p = 0.60) in women, 3.41 (2.51–4.64, p < 0.001) in men and 2.30 (0.87–6.05, p = 0.12) in women, 4.74 (1.91–11.70, p < 0.001) in men and 13.99 (7.23–27.09, p < 0.001) in women and 10.5 (8.02–13.8, p < 0.001) in men and 30.0 (18.0–50.0, p < 0.001) in women. Moreover, the risk of incident diabetes of the groups with ectopic fat obesity were almost higher than that of the four groups without ectopic fat obesity.ConclusionEctopic fat obesity presented the greatest risk of incident type 2 diabetes.

Impact of fatty liver disease and metabolic syndrome on incident type 2 diabetes; a population based cohort study

Fatty liver disease and metabolic syndrome (MetS) are both shown to increase the risk of type 2 diabetes. The aim of this study was to investigate the combined effect of fatty liver and MetS on incident diabetes. In this cohort study of 17,810 participants, fatty liver was diagnosed by abdominal ultrasonography and MetS was defined by a joint interim statement. We divided the participants into four groups according to the presence of fatty liver and/or MetS. Type 2 diabetes was defined as HbA1c ≥6.5%, fasting plasma glucose ≥7.0 mmol/L or treatment for diabetes. During the follow up examination (median 5.1 years), 804 participants developed diabetes. Compared with non-MetS without fatty liver, hazard ratios (HR) for incident diabetes after adjusting for age, body mass index, smoking status, exercise habit, alcohol consumption, family history of diabetes logarithm of alanine aminotransferase and fasting plasma glucose, were as follow: 2.35 (95 % CI 1.91-2.89, p<0.001) in non-MetS with fatty liver, 1.70 (95% CI 1.30-2.20, p<0.001) in MetS without fatty liver, and 2.33 (95% CI 1.85-2.94, p<0.001) in MetS with fatty liver. In addition, adjusted HRs for incident diabetes compared with MetS without fatty liver were 1.39 (95% CI 1.07-1.80, p=0.012) in non-MetS with fatty liver and 1.38 (95% CI 1.07-1.79, p=0.013) in MetS with fatty liver. Fatty liver affects more on the risk of incident diabetes than MetS. To prevent the further risk of diabetes, we should pay more attention to fatty liver.

Metabolically healthy obesity without fatty liver and risk of incident type 2 diabetes: A meta-analysis of prospective cohort studies

OBJECTIVE A meta-analysis indicated that metabolically healthy obesity (MHO) presents a risk of incident type 2 diabetes, but it has not yet been established whether MHO without fatty liver (w/o FL) also presents a risk of incident diabetes. METHODS We searched the MEDLINE and Embase databases to identify relevant prospective cohort studies and we supplemented the search with original data from the NAGALA (NAfld in Gifu Area, Longitudinal Analysis) study, defining MHO as a body mass index (BMI) ≥25 kg/m2 plus the presence of non or one of the following factors: hypertension, impaired fasting glucose, low high-density lipoprotein cholesterol, and hypertriglyceridemia. Using a random effects model, we calculated the pooled relative risks (RRs) and 95% confidence intervals (CIs) of incident diabetes. RESULTS Our meta-analysis included three studies from the databases plus the NAGALA study, with a total of 134,667 subjects, including 8675 MHO subjects w/o FL and 7218 MHO subjects with fatty liver (wFL). Compared to the metabolically healthy non-overweight subjects w/o FL, the RRs of incident diabetes in the MHO w/o FL and MHO wFL groups were 1.42 (95%CI 1.11-1.77) and 3.28 (95%CI 2.30-4.67). CONCLUSIONS Our meta-analysis results demonstrate that the MHO phenotype, with or without fatty liver, presents a risk of the development of type 2 diabetes. Individuals with MHO who do not have fatty liver should be monitored carefully - similarly to those with fatty liver - for the development of diabetes.

Correlation between ultrasound-diagnosed non-alcoholic fatty liver and periodontal condition in a cross-sectional study in Japan

This cross-sectional study investigated the relationship between periodontal condition and ultrasound-diagnosed non-alcoholic fatty liver disease (NAFLD) in a Japanese oral health check population. A total of 1226 consecutive participant were enrolled in the study. Abdominal ultrasonography was applied to diagnose NAFLD. Of the study participants, 339 (27.7%) had ultrasonography-diagnosed NAFLD. The participants with NAFLD had a significantly higher prevalence of probing pocket depth (PPD) ≥ 4 mm (86.7%) than those without NAFLD (72.9%) (p < 0.05). After adjusting for gender, age, Brinkman index, regular exercise habits, body mass index, number of teeth present, presence of periodontitis, blood pressure, and serum parameters, there was a statistically significant difference in the adjusted odds ratios of having PPD ≥ 4 mm for NAFLD (Odds ratio = 1.881, 95% confidence interval 1.184–2.987, p < 0.01). Having PPD ≥ 4 mm may be a risk factor for ultrasound-diagnosed NAFLD in this cross-sectional study of a Japanese oral health check population.

Nonalcoholic fatty liver disease remission in men through regular exercise

Recent cross-sectional and randomized controlled studies of small sample sizes revealed that regular exercise is effective for improving nonalcoholic fatty liver disease. However, there has been no large-scale longitudinal study addressing the effect of regular exercise on remission of nonalcoholic fatty liver disease. Thus, we investigated the impact of exercise on the natural history of nonalcoholic fatty liver disease. We analyzed 1,010 (860 men and 150 women) Japanese participants who received health checkups repeatedly over 10 years by a historical cohort study and were diagnosed with nonalcoholic fatty liver disease at baseline. Regular exercise was defined as participating in any kind of sports at least once a week. Nonalcoholic fatty liver disease was diagnosed by ultrasonographic images. During 10 years of follow-up, remission of nonalcoholic fatty liver disease was observed in 46.0% (396/860) of men and 48.7% (73/150) of women. In men, the adjusted hazard ratio of regular exercise for remission of nonalcoholic fatty liver disease was 1.46 (95% confidence interval 1.10–1.95, p = 0.010). However, this was not significant in women. Exercise at least once a week is implicated in the remission of nonalcoholic fatty liver disease in men.

Low urine pH is a risk for non-alcoholic fatty liver disease: A population-based longitudinal study

BACKGROUND Low urine pH has a close association with insulin resistance. This study was aimed to investigate the association between urine pH and incident non-alcoholic fatty liver disease (NAFLD), which is associated with insulin resistance. SUBJECTS AND METHODS In this historical cohort study of 11,012 participants (5503 men and 5509 women), we investigated the effect of urine pH on incident NAFLD. NAFLD was defined as having fatty liver diagnosed by abdominal ultrasonography and excluding the participants consumed ethanol over 60g/day for men and 40g/day for women. We divided the participants into three groups according to urine pH; the lowest group (urine pH≤5.5), the middle group (urine pH=6.0) and the highest group (urine pH≥6.5). Cox proportional hazards models was performed to investigate the effect of urine pH on incident NAFLD, adjusting for age, sex, body mass index, smoking, exercise, alcohol consumption, alanine aminotransferase, triglycerides, systolic blood pressure, uric acid and fasting plasma glucose. RESULTS Over the median 6.8-year follow-up duration, 2023 participants developed NAFLD, and the crude proportions were 20.3% (case/N=1104/5447) in the lowest urine pH group, 16.3% (487/2989) in the middle urine pH group and 16.8% (432/2576) in the highest urine pH group. The lowest urine pH group showed a significantly higher risk for incident NAFLD than the highest urine pH group (adjusted hazard ratio 1.48, 95% confidence interval 1.31-1.66, P<0.001). CONCLUSION Low urine pH is associated with incident NAFLD. Our findings indicate that urine pH can be an additional data when considering further diagnostic investigation for NAFLD in patients who have other risk factors.