Nonalcoholic fatty liver disease is a risk factor for glucose intolerance onset in men regardless of alanine aminotransferase status.

INTRODUCTION: Fatty liver disease (FLD) is a surrogate condition for glucose intolerance development. FLD may involve normal or abnormal liver enzyme levels. Whether FLD is a risk factor for glucose intolerance, regardless of liver enzyme levels, remains unknown. We assessed relationships between the development of impaired fasting glucose (IFG) and FLD, liver enzyme abnormalities, and alcohol consumption. MATERIALS AND METHODS: We retrospectively evaluated 8,664 participants with more than two annual health check-ups. Participants were classified according to sex, alcohol consumption, alanine aminotransferase (ALT) levels, and fatty liver status. RESULTS: In univariate analyses, IFG onset among men was related to normal or high ALT levels with FLD in the nonalcoholic and alcoholic groups (P-trend < 0.01). In multivariate analyses, IFG onset among nonalcoholic men was associated with normal or high ALT levels with FLD, independent of potential confounding factors (P-trend < 0.01). However, IFG onset was non-independently associated with any condition among alcoholic men. In univariate analyses, IFG onset among women was related to normal or high ALT levels with FLD in the nonalcoholic group (P-trend < 0.01) and high ALT levels with FLD in the alcoholic group (P-trend < 0.05). In multivariate analyses, IFG onset was independently associated with only normal ALT levels in nonalcoholic FLD women. CONCLUSIONS: Among nonalcoholic men and women, FLD was a risk factor for IFG onset, including normal ALT concentrations. Care is needed for individuals with nonalcoholic FLD, regardless of liver injury, possibly helping reduce glucose intolerance risk.

The Serum Creatinine Level Might Be Associated with the Onset of Impaired Fasting Glucose: A Community-based Longitudinal Cohort Health Checkup Study.

Objective Skeletal muscle is the main target organ for glycemic control, and the serum creatinine level is a convenient indicator of the skeletal muscle mass. This study aimed to assess the potential relationship between the serum creatinine level and the onset of impaired fasting glucose (IFG). Methods In this large, community-based, retrospective longitudinal cohort study, we examined the records of 7,905 Japanese participants (3,863 men, 4,042 women) of 18-80 years of age who underwent annual health checkups at a single center between April 2003 and August 2013. After applying the exclusion criteria, 6,490 participants were reviewed to identify those with the onset of IFG, defined as a fasting plasma glucose ≥6.11 mM. Among the participants, 278 met the criterion for the onset of IFG during the observation period. Results Creatinine levels were higher in male subjects who exercised periodically and were exercise conscious in comparison to those who did not exercise, and were higher in female subjects who exercised periodically in comparison to female subjects who did not exercise and who were not exercise conscious. Additionally, the serum creatinine level was negatively associated with the onset of IFG in both men [adjusted hazard ratio, 0.98; 95% confidence interval (CI), 0.96-0.99; p=0.008] and women (adjusted hazard ratio, 0.94; 95% CI, 0.91-0.97; p<0.001) after adjustment for variables previously reported to be risk factors for the onset of glucose intolerance and factors associated with chronic kidney disease. Conclusion A low creatinine level might be associated with the onset of IFG. Moreover, the fact that serum creatinine levels increase with exercise might demonstrate the importance of exercise therapy.

Low Urine pH Is Associated with Non-alcoholic Fatty Liver Disease: A Community-based Cross-sectional Study.

Objective Low urine pH is associated with several metabolic diseases, such as dyslipidemia, diabetes, and metabolic syndrome. However, the association between low urine pH and non-alcoholic fatty liver disease (NAFLD) remains unknown. Therefore, we conducted a community-based cross-sectional study to investigate this association. Methods Between April 2013 and March 2014, the records of 4,945 Japanese subjects who had undergone annual health checkups were reviewed to identify subjects who met the diagnostic criteria for NAFLD. Patients Based on urine pH, the participants were classified into four groups; a low urine pH was defined as ≤5.5. Of the 3,411 subjects who qualified for enrollment, 1,028 met the diagnostic criteria for NAFLD. Results The prevalence of NAFLD was significantly increased with decreasing urine pH in both men and women (p<0.01 and p=0.02, respectively). A multivariate analysis, including adjustments for age, metabolic markers, and the renal function, showed a significant association between low urine pH and NAFLD in men and women (odds ratio, 1.37; 95% confidence interval, 1.01-1.85, p=0.04 and odds ratio, 1.73; 95% confidence interval, 1.15-2.62, p<0.01, respectively). Conclusion Our study indicates that NAFLD is associated with a low urine pH in both sexes, findings that might help clinicians identify patients at high risk for NAFLD.

Cigarette smoking is a risk factor for the onset of fatty liver disease in nondrinkers: A longitudinal cohort study.

BACKGROUND: The effect of cigarette smoking on the onset of nonalcoholic fatty liver disease (NAFLD) is unclear, especially that associated with drinking small amounts of alcohol. We conducted a longitudinal study to investigate the relationship between cigarette smoking and NAFLD onset, which was stratified according to the amount of alcohol consumed. METHODS: We enrolled 7,905 Japanese subjects who had received annual health checkups more than twice between April 2003 and August 2013, 4,045 of whom met at least one of the following exclusion criteria and were excluded: (a) fatty liver at baseline; (b) hepatitis B or hepatitis C; (c) alcohol consumption (men: ≥210 g/wk; women: ≥140 g/wk); (d) change in alcohol drinking status between baseline and the study's endpoint; (e) change in cigarette smoking habits between baseline and the study's endpoint; or (f) current treatment with antidiabetic agents, antihypertensive agents, and/or lipid-lowering agents. The remaining 3,860 subjects (1,512 men, 2,348 women) were divided into two groups based on average alcohol consumption. RESULTS: After adjusting for the variables associated with metabolic disease, smoking was associated with fatty liver disease onset compared with nonsmokers in nondrinkers (adjusted hazard ratio = 1.988, 95% confidence interval 1.057-3.595; p = 0.034). No association was found between smoking and fatty liver disease onset in the low alcohol consumption group (men: <210 g alcohol/week; women: <140 g alcohol/week). The fatty liver disease incidence increased significantly among the nondrinkers as the number of cigarettes smoked increased (p = 0.001). CONCLUSIONS: Cigarette smoking may be a significant risk factor associated with NAFLD onset in nondrinkers. These results may help clinicians to identify patients who are at a high risk of developing NAFLD and to prevent the progression of NAFLD by promoting earlier interventions that help people discontinue unhealthy lifestyle habits.

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

AIMS/INTRODUCTION: 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. MATERIALS AND METHODS: We enrolled 4,945 Japanese individuals (2,490 men and 2,455 women), who had undergone annual health checkups. To investigate the relationship between low urine pH and abnormal glucose tolerance, participants were divided into three groups based on their fasting plasma glucose levels (<6.11 mmol/L, 6.11-6.99 mmol/L and ≥6.99 mmol/L), and three groups based on their glycated hemoglobin levels (≤44.3 mmol/mol, 44.3-47.5 mmol/mol and ≥47.5 mmol/mol). To examine the effects of urine pH on abnormal glucose tolerance, participants were categorized into five groups based on their urine pH (5.0, 5.5, 6.0, 6.5 and ≥7.0). RESULTS: Multivariate analysis adjusted for age, body mass index, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, uric acid, creatinine and antidiabetic agent use showed significant associations between low urine pH and both high fasting plasma glucose and high glycated hemoglobin levels (P for trend = 0.0260, 0.0075) in men. Furthermore, after the same adjustments, prevalence rates of abnormal glucose tolerance (≥6.11 mmol/L and ≥6.99 mmol/L), increased significantly as urine pH levels decreased (P for trend = 0.0483, 0.0181) in men. In women, a similar trend was observed without a significant difference. CONCLUSIONS: Low urine pH is significantly associated with abnormal glucose tolerance; therefore, measuring urine pH might prove useful for identifying patients at high risk for diabetes.

Differences in the risk of fatty liver for onset of impaired fasting glucose according to baseline plasma glucose levels.

BACKGROUND: It remains unclear whether fatty liver is a risk factor for the onset of abnormal glucose tolerance in any patient. The objective of this study was to clarify the relationship between fatty liver and the onset of impaired fasting glucose according to baseline fasting plasma glucose (FPG) levels. METHODS: This community-based longitudinal cohort study included 7,905 adults (3,863 men, 4,042 women; age range, 18-80 years) who had at least two annual checkups between 2003 and 2013. Those with FPG levels ≥110 mg/dl, taking anti-diabetic agents, and/or testing positive for hepatitis B surface antigen or anti-hepatitis C virus antibody were excluded, leaving 7,203 participants eligible for inclusion. All participants were divided into quartiles derived from their FPG levels at baseline. FPG ≥110 mg/dl during the observation period was defined as onset of IFG. RESULTS: Onset of IFG was found in 7.7 % of men and 2.1 % of women (p < 0.001). After adjusting for age, body mass index, systolic blood pressure, triacylglycerol, high-density lipoprotein cholesterol, uric acid, creatinine, family history of diabetes, alcohol consumption, and current smoking, a positive association was found between fatty liver and the onset of IFG in both sexes with the highest quartile of FPG levels [men: adjusted hazard ratio (aHR) 1.823, 95 % confidence interval (CI) 1.316-2.534, p < 0.001; women: aHR 2.016, 95 % CI 1.117-3.6, p = 0.02]. CONCLUSIONS: Our results suggest that fatty liver is independently associated with an increased risk of developing IFG in individuals with high FPG.

Low alcohol consumption increases the risk of impaired glucose tolerance in patients with non-alcoholic fatty liver disease.

BACKGROUND: Fatty liver disease is associated with glucose intolerance and hepatic insulin resistance. However, there are distinct etiologies for alcoholic versus non-alcoholic fatty liver disease (NAFLD), and it is unknown whether alcohol consumption influences the onset of glucose intolerance in fatty liver disease patients. Therefore, we investigated the relationship between fatty liver disease and the onset of impaired fasting glucose (IFG) with respect to alcohol consumption. METHODS: The records of 6804 Japanese subjects were reviewed to identify those meeting the criteria for IFG. Male and female subjects were classified into five and four groups, respectively, based on average alcohol consumption (g/week). IFG onset was defined as fasting plasma glucose levels ≥110 mg/dl. RESULTS: In the non-drinker, >0-70 g/week, >70-140 g/week, >140-210 g/week (men only), and >210 g/week (men only) or >140 g/week (women only) groups, 7.3, 6.7, 6.4, 9, and 6.4 % of men and 2, 1.7, 3.1, and 3.2 % of women, respectively, developed IFG. Fatty liver was positively associated with the onset of IFG in men of the >0-70 g/week group (adjusted hazard ratio [aHR], 2.808; 95 % confidence interval [CI] 1.605-5.049, p < 0.001) and women of the >70-140 g/week group (aHR, 4.193; 95 % CI, 1.036-14.584, p = 0.045) after adjusting for previously reported IFG risk factors. No associations were observed in the other groups. CONCLUSIONS: A small amount of alcohol consumption is a significant risk factor for the onset of IFG in NAFLD patients; onset risk differs according to the amount of alcohol consumption.

Short sleep duration reduces the risk of nonalcoholic fatty liver disease onset in men: a community-based longitudinal cohort study.

BACKGROUND: Epidemiologic studies show an association between short sleep duration and the presence of nonalcoholic fatty liver disease (NAFLD). This study examined the association between short sleep duration and the onset of NAFLD. METHODS: This community-based, retrospective, longitudinal cohort study included 6,370 Japanese subjects who had undergone annual health check-ups more than twice at a single center between April 2003 and March 2010. After excluding 3,941 subjects, the records of 2,429 Japanese subjects were reviewed. RESULTS: Two groups comprised the study cohort: those with short (≤ 6 h) sleep durations (n = 1,543) and those with moderate (7-8 h) sleep durations (n = 886). During the observation period, 296 subjects developed NAFLD. Multivariate analysis identified an association between short sleep duration and the reduced onset of NAFLD in men (odds ratio: 0.551, 95% confidence interval 0.365-0.832, p = 0.005). There was no association between short sleep duration and NAFLD onset in women. The prevalence of NAFLD onset in men increased significantly as sleep duration increased, as follows: 12.5, 18.4, and 27.4% among subjects who had sleep durations of ≤ 4, 5-6, and 7-8 h, respectively (p = 0.02). CONCLUSIONS: This study demonstrates an association between sleep duration and NAFLD onset. Short sleep duration reduced the risk of NAFLD onset in men. Correct recognition is important to prevent disease progression and further complications.

Significance of exercise in nonalcoholic fatty liver disease in men: a community-based large cross-sectional study.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a risk factor for diabetes and cardiovascular disease that could progress to nonalcoholic steatohepatitis, cirrhosis, and liver failure. We aimed to assess the relationship between NAFLD and lifestyle habits. METHODS: Using a community-based, cross-sectional design, the records of 11,094 Japanese subjects who had undergone at least 1 annual health checkup were reviewed. RESULTS: Of the 6,370 subjects who qualified for enrolment, 1,346 met the diagnostic criteria for NAFLD. The prevalence rate (PR) of NAFLD increased significantly to 36.6, 41.5, and 41.1 % with no snacking, snacking less than once/day, and snacking ≥2 times/day, respectively, in men (P = 0.0495) and to 10.8, 11.7, and 15.3 %, respectively, in women (P = 0.002). In men, the NAFLD PR decreased significantly to 48.8, 36.9, and 29.9 % with no exercise, exercise consciousness, and periodical exercise, respectively (P < 0.001). In women, the NAFLD PR decreased significantly to 19.3, 13.5, 11, and 8 % with sleep durations of ≤4, 5-6, 7-8, and ≥9 h, respectively (P = 0.003). Periodical exercise was identified as an independent factor associated with NAFLD in men (odds ratio 0.707, 95 % confidence interval 0.546-0.914; P = 0.008). CONCLUSIONS: Performing regular exercise was associated with a reduced risk for NAFLD in men. Men with a high risk for NAFLD can be identified using questionnaires on exercise in an outpatient setting. Disease progression and further complications may be prevented by educating high-risk NAFLD patients about the importance of exercise.

Hyperuricemia is a risk factor for the onset of impaired fasting glucose in men with a high plasma glucose level: a community-based study.

BACKGROUND: It is not clear whether elevated uric acid is a risk factor for the onset of impaired fasting glucose after stratifying by baseline fasting plasma glucose levels. We conducted a community-based retrospective longitudinal cohort study to clarify the relationship between uric acid levels and the onset of impaired fasting glucose, according to baseline fasting plasma glucose levels. METHODS: We enrolled 6,403 persons (3,194 men and 3,209 women), each of whom was 18-80 years old and had > 2 annual check-ups during 2003-2010. After excluding persons who had fasting plasma glucose levels ≥ 6.11 mM and/or were currently taking anti-diabetic agents, the remaining 5,924 subjects were classified into quartiles according to baseline fasting plasma glucose levels. The onset of impaired fasting glucose was defined as fasting plasma glucose ≥ 6.11 mM during the observation period. RESULTS: In the quartile groups, 0.9%, 2.1%, 3.4%, and 20.2% of the men developed impaired fasting glucose, respectively, and 0.1%, 0.3%, 0.5%, and 5.6% of the women developed impaired fasting glucose, respectively (P trend <0.001). After adjusting for age, body mass index, systolic blood pressure, triacylglycerols, high density lipoprotein-cholesterol, creatinine, fatty liver, family history of diabetes, alcohol consumption, and current smoking, uric acid levels were positively associated with onset of impaired fasting glucose in men with highest-quartile fasting plasma glucose levels (adjusted hazard ratio, 1.003; 95% confidence interval, 1.0001-1.005, P = 0.041). CONCLUSIONS: Among men with high fasting plasma glucose, hyperuricemia may be independently associated with an elevated risk of developing impaired fasting glucose.

Body mass index is the most useful predictive factor for the onset of nonalcoholic fatty liver disease: a community-based retrospective longitudinal cohort study.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) can progress to advanced liver disease and non-liver-related diseases. To prevent NAFLD onset, clinicians must be able to easily identify high-risk NAFLD patients so that intervention can begin at an earlier stage. We sought to identify the predictive factors for NAFLD onset. METHODS: In a community-based, longitudinal design, the records of 6,403 Japanese subjects were reviewed to identify those meeting the criteria for NAFLD onset. Univariate and multivariate logistic regression analyses were used to identify predictive factors for NAFLD onset. The accuracy of different models was evaluated according to their areas under the receiver operating characteristic curves. Comparative risk analysis was performed using the Kaplan-Meier method. RESULTS: Multivariate analysis of 400 subjects who met the criteria for the onset of NAFLD during the observation period confirmed that body mass index (BMI) at baseline was the most useful predictive factor for NAFLD onset in both sexes. Cutoff levels of BMI for NAFLD onset were estimated at 23 kg/m2 for men and 22.2 kg/m2 for women. The cumulative onset rate of NAFLD was significantly higher in the high BMI group than in the low BMI group in both sexes (P < 0.001). CONCLUSION: BMI was confirmed as the most useful predictive factor for NAFLD onset in both sexes; its cutoff levels were similar to those recommended by the World Health Organization for helping to prevent metabolic disease. An accurate BMI cutoff level will enable clinicians to identify subjects at risk for NAFLD onset.

Metabolic markers and ALT cutoff level for diagnosing nonalcoholic fatty liver disease: a community-based cross-sectional study.

BACKGROUND: Untreated nonalcoholic fatty liver disease (NAFLD) may progress to liver cirrhosis or failure and is associated with the development of hepatocellular carcinoma, diabetes, and cardiovascular disease. It is therefore essential to diagnose and treat NAFLD at an early stage. To assist in this effort, this retrospective study explored the risk factors for NAFLD, and derived new surrogates, a revised alanine aminotransferase (ALT) cutoff level and a novel NAFLD index, to identify previously undiagnosed cases of NAFLD. METHODS: Using a community-based, cross-sectional design, the records of 6,370 Japanese subjects who had undergone at least 1 annual health check-up were reviewed for the identification of subjects meeting the diagnostic criteria for NAFLD and the variables associated with NAFLD for the estimation of ideal ALT cutoff levels. RESULTS: The results of multivariate analysis of the 1,346 subjects who met the diagnostic criteria for NAFLD confirmed that metabolic disease markers and a novel NAFLD index, using the variables derived from multivariate analysis, were also markers of NAFLD. The ALT cutoff levels for NAFLD diagnosis were estimated at 25 U/L for males and 17 U/L for females. CONCLUSIONS: ALT level and the novel NAFLD index were confirmed to be surrogate markers for NAFLD in addition to metabolic disease markers. The ALT cutoff level used in NAFLD diagnosis should be revised downward to identify subjects at risk of NAFLD to prevent NAFLD progression and the development of associated diseases.