Burden of gallstone disease in the United States population: Prepandemic rates and trends

BACKGROUND

Gallstone disease is one of the most common digestive disorders in the United States and leads to significant morbidity, mortality, and health care utilization.

AIM

To expand on earlier findings and investigate prepandemic rates and trends in the gallstone disease burden in the United States using national survey and claims databases.

METHODS

The National Ambulatory Medical Care Survey, National Inpatient Sample, Nationwide Emergency Department Sample, Nationwide Ambulatory Surgery Sample, Vital Statistics of the United States, Optum Clinformatics® Data Mart, and Centers for Medicare and Medicaid Services Medicare 5% Sample and Medicaid files were used to estimate claims-based prevalence, medical care including cholecystectomy, and mortality with a primary or other gallstone diagnosis. Rates were age-adjusted (for national databases) and shown per 100000 population.

RESULTS

Gallstone disease prevalence (claims-based, 2019) was 0.70% among commercial insurance enrollees, 1.03% among Medicaid beneficiaries, and 2.09% among Medicare beneficiaries and rose over the previous decade. Recently, in the United States population, gallstone disease contributed to approximately 2.2 million ambulatory care visits, 1.2 million emergency department visits, 625000 hospital discharges, and 2000 deaths annually. Women had higher medical care rates with a gallstone disease diagnosis, but mortality rates were higher among men. Hispanics had higher ambulatory care visit and hospital discharge rates compared with Whites, but not mortality rates. Blacks had lower ambulatory care visit and mortality rates, but similar hospital discharge rates compared with whites. During the study period, ambulatory care and emergency department visit rates with a gallstone disease diagnosis rose, while hospital discharge and mortality rates declined. Among commercial insurance enrollees, rates were higher compared with national data for ambulatory care visits and hospitalizations, but lower for emergency department visits. Cholecystectomies performed in the United States included 605000 ambulatory laparoscopic, 280000 inpatient laparoscopic, and 49000 inpatient open procedures annually. Among commercial insurance enrollees, rates were higher compared with national data for laparoscopic procedures.

CONCLUSION

The gallstone disease burden in the United States is substantial and increasing, particularly among women, Hispanics, and older adults with laparoscopic cholecystectomy as the mainstay treatment. Current practice patterns should be monitored for better health care access.

Longitudinal Study of Comorbidities and Clinical Outcomes in Persons with Gallstone Disease Using Electronic Health Records

BACKGROUND

Gallstone disease (GSD) is common and leads to significant morbidity, mortality, and health care utilization in the USA. We examined comorbidities and clinical outcomes among persons with GSD using electronic health records (EHR).

METHODS

In this retrospective study of 1,381,004 adults, GSD was defined by ICD-9 code 574 or ICD-10 code K80 using Optum® longitudinal EHR from January 2007 to March 2021. We obtained diagnosis, procedure, prescription, and vital sign records and evaluated associations between demographics, comorbidities, and medications with cholecystectomy, digestive cancers, and mortality.

RESULTS

Among persons with GSD, 30% had a cholecystectomy and were more likely to be women, White, and younger, and less likely to have comorbidities, except for obesity, gastroesophageal reflux disease (GERD), abdominal pain, hyperlipidemia, and pancreatitis. Among persons with GSD, 2.2% had a non-colorectal digestive cancer diagnosis during follow-up and risk was 40% lower among persons with a cholecystectomy. Non-colorectal digestive cancer predictors included older age, male sex, non-White race-ethnicity, lower BMI, other cancers, diabetes, chronic liver disease, pancreatitis, GERD, and abdominal pain. Among persons with GSD, mortality was 15.1% compared with 9.7% for the whole EHR sample. Persons with a cholecystectomy had 40% lower mortality risk and mortality predictors included older age, male sex, Black race, lower BMI, and most comorbidities.

CONCLUSIONS

In this EHR analysis of persons with GSD, 30% had a cholecystectomy. Mortality was higher compared with the whole EHR sample. Persons with cholecystectomy were less likely to have non-colorectal digestive cancer or to die.

The Burden of Digestive Diseases in the United States Population

Background and rationale

Digestive diseases are common and lead to significant morbidity, mortality, and health care utilization. We used national survey and claims databases to expand on earlier findings and investigate current trends in the digestive disease burden in the United States.

Methods

The National Ambulatory Medical Care Survey, Nationwide Emergency Department Sample, National Inpatient Sample, Vital Statistics of the U.S., Surveillance, Epidemiology, and End Results Program, Optum Clinformatics® Data Mart, and Centers for Medicare and Medicaid Services Medicare 5% Sample databases were used to estimate medical care, mortality, cancer incidence, and claims-based prevalence with a digestive disease diagnosis. Rates were age-adjusted (for national databases) and shown per 100,000 population.

Results

For all digestive diseases, prevalence (claims-based, all-listed diagnoses) was 30.5% among commercial insurance enrollees (2020) and 53.1% among Medicare beneficiaries (2019). In the U.S. population, digestive diseases contributed to approximately 126 million ambulatory care visits (2015), 41 million emergency department visits (2018), 16 million hospital discharges (2018), and 472,000 deaths (2019) annually. Prevalence, medical care, and mortality rates with a digestive disease diagnosis were higher among children and younger adults (except for emergency department visits) and then increased with age. Women had higher prevalence and medical care rates with a digestive disease diagnosis, but mortality rates were higher among men. Prevalence and medical care rates with a digestive disease diagnosis were higher among Blacks, followed by Whites, then Hispanics, and lowest among Asians. Mortality rates were higher among Blacks compared with Whites and lower among Hispanics compared with non-Hispanics. Between 2004 and the most recent year, ambulatory care visit rates with a digestive disease diagnosis increased by 4%, hospital discharge rates decreased by 3%, and mortality rates decreased by 7%. Among commercial insurance enrollees, rates were higher compared with national data for ambulatory care visits and hospital discharges, but lower for emergency department visits. The medical care use and mortality burdens varied among individual digestive diseases.

Conclusion

The digestive disease burden in the United States is substantial, particularly among Blacks and older adults.

Increasing gallstone disease prevalence and associations with gallbladder and biliary tract mortality in the US

BACKGROUND AND AIMS

We examined gallbladder and biliary tract mortality predictors in the US National Health and Nutrition Examination Survey (NHANES), 1988-1994, with 31 years of linked mortality data, and gallstone disease prevalence trends and associations in NHANES 2017-March 2020 prepandemic data.

APPROACH AND RESULTS

In NHANES 1988-1994, 18,794 participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to the National Death Index through 2019. In NHANES 2017-March 2020, gallstone disease history was ascertained from 9232 adults. During NHANES 1988-2019 follow-up (median, 23.3 y), 8580 deaths occurred from all causes and 72 deaths with gallbladder or biliary tract disease. In multivariable-adjusted analysis, older age, male sex, prediabetes or diabetes, and physical inactivity were associated with gallbladder and biliary tract mortality, and non-Hispanic Black and Mexican American race-ethnicity were inversely associated. Between 1988-1994 and 2017-March 2020, gallstone disease prevalence increased from 7.4% to 13.9% and gallbladder surgery from 6.0% to 11.6%. In 2017-March 2020 in multivariable-adjusted analysis, female sex, diabetes, liver disease, proton pump inhibitors, abdominal pain, increased age, BMI, and liver stiffness were associated with gallstone disease, and non-Hispanic Black and non-Hispanic Asian race and alcohol were inversely associated.

CONCLUSIONS

In the US population, gallstone disease prevalence doubled over 3 decades, possibly because of the worsening of metabolic risk factors and growth of laparoscopic cholecystectomy. Gallbladder and biliary tract mortality and gallstone disease associations included factors such as prediabetes or diabetes, liver stiffness and proton pump inhibitors.

Transient Elastography Measures of Hepatic Steatosis and Fibrosis Are Associated With Body Composition Among US Adolescents

OBJECTIVES

Obesity-related fatty liver disease impacts long-term adolescent liver health. We examined transient elastography assessed hepatic steatosis and fibrosis distributions and relationships with body composition and lifestyle factors in a United States national adolescent population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 1080 non-Hispanic white, non-Hispanic black, non-Hispanic Asian, and Hispanic boys and girls aged 12-19 years in the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Participants underwent anthropometry and dual-energy x-ray absorptiometry (DXA).

RESULTS

Compared with girls, boys had higher mean CAP (223.7 dB/m vs 215.3 dB/m) and liver stiffness (5.1 kPa vs 4.9 kPa). CAP and liver stiffness increased markedly with body mass index (BMI). In multivariable-adjusted analysis, CAP in the upper quartile was associated with Hispanic and non-Hispanic Asian ethnicity and increased BMI, waist-to-hip ratio, systolic blood pressure, and sedentary time, and decreased physical activity and Healthy Eating Index-2015 score. In multivariable-adjusted analysis, liver stiffness in the upper quartile was associated with male sex, non-Hispanic black ethnicity, and increased BMI, alanine aminotransferase, CAP, and serum cotinine. DXA total percent fat and trunk fat percent were positively related to CAP ( P < 0.001 for each), but not to liver stiffness with multivariable adjustment. Results were similar with CAP and liver stiffness as continuous characteristics.

CONCLUSIONS

In US adolescents, increased anthropometric and DXA body composition measures and lifestyle factors were associated with higher CAP and liver stiffness. Transient elastography and similar noninvasive markers may be utilized for early detection of liver disease in high-risk pediatric populations.

Prepandemic Prevalence Estimates of Fatty Liver Disease and Fibrosis Defined by Liver Elastography in the United States

BACKGROUND AND AIMS

Fatty liver disease is a growing public health burden. We estimated prepandemic fatty liver disease prevalence determined by transient elastography-assessed hepatic steatosis and fibrosis, and examined associations with lifestyle and other factors in a United States population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 7923 non-Hispanic white, non-Hispanic black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 prepandemic data.

RESULTS

The prevalence of fatty liver disease (CAP > 300 dB/m) was 28.8% and of fibrosis (liver stiffness > 8 kPa) was 10.4%. Only 7.2% of participants with fatty liver disease and 10.9% with fibrosis reported being told by a health care provider that they had liver disease. In addition to known risk factors such as metabolic factors and ALT, persons with fatty liver disease were less likely to meet physical activity guidelines, more likely to be sedentary for ≥ 12 h a day, and reported a less healthy diet. Persons with fibrosis were less likely to have a college degree and reported a less healthy diet.

CONCLUSIONS

In the U.S. population, most persons with fatty liver disease are unaware of their condition. Physical activity and dietary modifications might reduce the fatty liver disease burden. There is an urgent need for fatty liver disease management in high-risk individuals using transient elastography or other noninvasive methods to intervene in disease progression.

Transient Elastography-Assessed Hepatic Steatosis and Fibrosis Are Associated With Body Composition in the United States

BACKGROUND & AIMS

We examined transient elastography assessed hepatic steatosis and fibrosis distributions and relationships with body composition in a representative United States population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 4870 non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Participants underwent anthropometry and dual-energy x-ray absorptiometry (DXA).

RESULTS

Compared to women, men had higher mean CAP (274.2 dB/m vs 254.4 dB/m) and liver stiffness (6.4 kPa vs 5.5 kPa). CAP and liver stiffness increased through middle age and markedly with BMI. In multivariate-adjusted analysis, CAP in the upper quartile was associated with increased age, BMI, waist-to-hip ratio, diabetes, hypertension, alanine aminotransferase (ALT) and C-reactive protein and decreased HDL cholesterol. After adjustment, non-Hispanic Blacks had lower CAP and non-Hispanic Asians had higher CAP. In multivariate-adjusted analysis, liver stiffness in the upper quartile was associated with male sex, increased age, BMI, diabetes, hepatitis C virus positivity, ALT and CAP. Lower stiffness among Non-Hispanic Asians was not significant after adjustment for BMI. DXA trunk and extremity fat mass were positively related to both CAP and liver stiffness with multivariate adjustment (P < .001 for each). Results were similar with CAP and liver stiffness as continuous characteristics.

CONCLUSIONS

In the United States population, increased anthropometric and DXA body composition measures were associated with higher CAP and liver stiffness. Racial-ethnic differences observed merit further research to elucidate the burden of obesity and liver health disparities.

Patatin-Like Phospholipase Domain-Containing Protein 3 I148M and Liver Fat and Fibrosis Scores Predict Liver Disease Mortality in the U.S. Population

BACKGROUND AND AIMS

Fatty liver causes premature death worldwide and requires long-term health care. We examined relationships of liver disease markers, including patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M, with mortality in the U.S. National Health and Nutrition Examination Survey, 1988-1994, with 27 years of linked mortality data.

APPROACH AND RESULTS

We studied 13,298 viral hepatitis negative adults who fasted at least 4 hours using the nonalcoholic fatty liver disease (NAFLD) liver fat score and NAFLD fibrosis score. PNPLA3 I148M was genotyped in a subgroup of participants from 1991 to 1994 (n = 5,640). Participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to the National Death Index through 2015. During follow-up (median, 23.2 years), cumulative mortality was 33.2% overall and 1.1% with liver disease, including primary liver cancer. Increased liver disease mortality was associated with PNPLA3 I148M (hazard ratio [HR], 2.9; 95% confidence interval [CI], 0.9-9.8) and 148M genotypes (HR, 18.2; 95% CI, 3.5-93.8), an intermediate (HR, 3.8; 95% CI, 1.3-10.7) or high (HR, 12.6; 95% CI, 4.3-36.3) NAFLD liver fat score, and a high NAFLD fibrosis score (HR, 12.2; 95% CI, 1.9-80.6) adjusted for risk factors. Survival curves suggest that increased mortality risk with two 148M alleles was greatest beginning in the second decade of follow-up. Overall, but not cardiovascular disease, mortality was associated with the PNPLA3 148M allele, and both mortality outcomes were associated with higher fat and fibrosis scores.

CONCLUSIONS

In the U.S. population, PNPLA3 I148M and higher NAFLD liver fat and fibrosis scores were associated with increased liver disease mortality. Genetic variant PNPLA3 I148M may complement other liver disease markers for NAFLD surveillance.

Liver fat scores predict liver disease mortality in the United States population

BACKGROUND

Fatty liver is a significant global public health burden, contributing to premature death.

AIM

To examine whether liver fat scores were associated with increased overall and disease-specific mortality in a United States (US) population-based survey with up to 27 years of linked mortality data.

METHODS

We studied 9200 fasted viral hepatitis-negative adults in the third National Health and Nutrition Examination Survey, 1988-1994. Liver fat was predicted using the US fatty liver index (US FLI), fatty liver index (FLI), non-alcoholic fatty liver disease liver fat score (NAFLD LFS), and hepatic steatosis index (HSI). Participants were passively followed up for mortality, identified by death certificate underlying or contributing causes, by linkage to National Death Index records through 2015. Mortality hazard ratios (HR) were calculated using Cox proportional hazards regression to adjust for mortality risk factors.

RESULTS

During follow-up (median, 23.3 years), cumulative mortality was 31.4% overall and 1.1% with liver disease, including primary liver cancer. Elevated liver disease mortality was associated with a high US FLI (HR, 5.7; 95% confidence interval (CI), 1.3-24.5), and intermediate (HR, 3.1; 95% CI, 1.1-9.1) or high (HR, 11.4; 95% CI, 2.9-44.4) NAFLD LFS, but not with a higher FLI or HSI. Overall and cardiovascular disease mortality was unassociated with higher liver fat scores.

CONCLUSIONS

In the US population, a higher US FLI and NAFLD LFS were associated with increased liver disease mortality, but not with other mortality outcomes. Liver fat scores may be useful for metabolic health surveillance and long-term liver disease risk stratification and may complement fibrosis markers for tracking.

Liver fibrosis scores predict liver disease mortality in the United States population

Fatty liver disease is common in the United States and worldwide due to changing lifestyles and can progress to fibrosis and cirrhosis contributing to premature death. We examined whether liver fibrosis scores were associated with increased overall and disease-specific mortality in a United States population-based prospective survey with up to 23 years of linked-mortality data. Data were analyzed from 14,841 viral hepatitis-negative adult participants in the third National Health and Nutrition Examination Survey, 1988-1994. Liver fibrosis was predicted using the aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis-4 (FIB-4) score, nonalcoholic fatty liver disease fibrosis score (NFS), and Forns score. Participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to National Death Index records through 2011. Hazard ratios (HR) for mortality were calculated using Cox proportional hazards regression to adjust for mortality risk factors. During follow-up, cumulative mortality was 28.0% from all causes and 0.82% with liver disease, including primary liver cancer. Elevated liver disease mortality was found with an intermediate to high APRI (HR, 9.44; 95% confidence interval [CI], 5.02-17.73), intermediate (HR, 3.15; 95% CI, 1.33-7.44) or high (HR, 25.14; 95% CI, 8.38-75.40) FIB-4 score, high NFS (HR, 6.52; 95% CI, 2.30-18.50), and intermediate (HR, 3.58; 95% CI, 1.78-7.18) or high (HR, 63.13; 95% CI, 22.16-179.78) Forns score. Overall mortality was also greater with higher fibrosis scores.

CONCLUSION

In the United States population, higher liver fibrosis scores were associated with increased liver disease and overall mortality. Liver health management with common clinical measures of fibrosis risk stratification merits further investigation. (Hepatology 2017;66:84-95).

Lower Prevalence of Celiac Disease and Gluten-Related Disorders in Persons Living in Southern vs Northern Latitudes of the United States

BACKGROUND & AIMS

The association between prevalence of celiac disease and geographic region is incompletely understood, but the occurrence of several autoimmune disorders has been found to vary along a North-South gradient. We examined geographic, demographic, and clinical factors associated with prevalence of celiac disease and gluten-free diet in the United States.

METHODS

In a population-based study, we analyzed data on gluten-related conditions from the National Health and Nutrition Examination Survey, from 2009 through 2014, on 22,277 participants 6 years and older. We identified persons with celiac disease based on results of serum tests for IgA against tissue transglutaminase and endomysium or on both a health care provider diagnosis and adherence to a gluten-free diet. Gluten avoidance without celiac disease was defined as adherence to a gluten-free diet without a diagnosis of celiac disease. We compared mean serum levels of biochemical and nutritional markers based on status of gluten-related conditions.

RESULTS

We found 0.7% of participants to have celiac disease and 1.1% of participants to avoid gluten without celiac disease. Celiac disease was more common among individuals who lived at latitudes of 35°-39° North (odds ratio, 3.2; 95% confidence interval, 1.4-7.1) or at latitudes of 40° North or more (odds ratio, 5.4; 95% CI, 2.6-11.3) than individuals who lived at latitudes below 35° North, independent of race or ethnicity, socioeconomic status, and body mass index. Gluten avoidance without celiac disease was more common among individuals who lived at latitudes of 40° North or more, independent of demographic factors and body mass index. Participants with undiagnosed celiac disease (identified by positive results from serologic tests) had lower mean levels of vitamin B-12 and folate (data collected from 2009 through 2012) than persons without celiac disease. Participants with a health care provider diagnosis of celiac disease had a lower mean level of hemoglobin than persons without celiac disease. Mean levels of albumin, calcium, iron, ferritin, cholesterol, vitamin B-6, and vitamin D (data collected from 2009 through 2010) did not differ between participants with gluten-related conditions and those without.

CONCLUSIONS

In the US population, a higher proportion of persons living at latitudes of 35° North or greater have celiac disease or avoid gluten than persons living south of this latitude, independent of race or ethnicity, socioeconomic status, or body mass index. Mean levels of vitamin B-12 and folate are lower in individuals with undiagnosed celiac disease, and levels of hemoglobin are lower in participants with a diagnosis of celiac disease, compared with individuals without celiac disease.

Less Hidden Celiac Disease But Increased Gluten Avoidance Without a Diagnosis in the United States: Findings From the National Health and Nutrition Examination Surveys From 2009 to 2014

OBJECTIVE

To investigate the trends in the prevalence of diagnosed celiac disease (CD), undiagnosed CD, and people without celiac disease avoiding gluten (PWAG) in the civilian noninstitutionalized US population from 2009 to 2014.

PATIENTS AND METHODS

We studied the occurrence of CD and PWAG in the 2009 to 2014 National Health and Nutrition Examination Surveys. The serum of all participants aged 6 years or older from the National Health and Nutrition Examination Surveys from 2009 to 2014 was tested for CD serology at Mayo Clinic. Participants were interviewed for a diagnosis of CD and the use of a gluten-free diet (GFD). The design effects of the survey and sample weights were incorporated in all statistical analyses.

RESULTS

In the US general population, the prevalence of CD did not change significantly from 0.7% (95% CI, 0.6%-0.8%) in 2009 to 2010 to 0.8% (95% CI, 0.4%-1.2%) in 2011 to 2012 to 0.7% (95% CI, 0.3%-1.0%) in 2013 to 2014. However, the prevalence of undiagnosed CD decreased from 0.6% in 2009 to 2010 to 0.3% in 2013 to 2014. In contrast, the prevalence of PWAG increased significantly from 0.5% (95% CI, 0.2%-0.9%) in 2009 to 2010 to 1.0% (95% CI, 0.6%-1.4%) in 2011 to 2012 to 1.7% (95% CI, 1.1%-2.4%) in 2013 to 2014 (P=.005 for trend).

CONCLUSION

Although the overall prevalence of CD remained stable from 2009 to 2014, the proportion of individuals with CD that is hidden considerably decreased. Moreover, the proportion of individuals without CD but following a GFD increased markedly from 2009 to 2014. Long-term health consequences of a GFD warrant further investigation.

Noninvasive fatty liver markers predict liver disease mortality in the U.S. population

Nonalcoholic fatty liver disease (NAFLD) contributes to premature death along with obesity, diabetes, and cardiovascular disease (CVD). We examined whether hepatic steatosis (HS) on ultrasound and liver enzyme activities were associated with increased liver disease mortality in the U.S. National Health and Nutrition Examination Survey (NHANES), 1988-1994, with up to 23 years of linked-mortality data. Survey-linked National Death Index records were analyzed among 14,527 adult participants who were negative for viral hepatitis B and C and iron overload. HS on ultrasound was categorized as normal, mild, moderate, or severe. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) elevation was defined as the highest sex-specific decile. Cumulative mortality was 36.2% from all causes, including 16.3% from CVD, 10.8% from cancer, 5.4% from diabetes, and 1.1% from liver disease. Severe HS was associated with increased liver disease mortality in both age-adjusted (hazard ratio [HR]: 3.92; 95% confidence interval [CI]: 1.49-10.27; P for trend: 0.011) and multivariate-adjusted analyses (HR, 2.68; 95% CI: 1.02-7.03; P for trend: 0.072). HS was not independently associated with mortality from all causes, CVD, cancer, or diabetes. Higher liver disease mortality was found with elevated ALT (HR, 4.08; 95% CI: 1.99-8.33), AST (HR, 4.33; 95% CI: 2.18-8.59), and GGT (HR, 7.91; 95% CI: 3.06-20.46). GGT elevation was associated with increased overall mortality (HR, 1.45; 95% CI: 1.21-1.74). Liver enzymes were otherwise unrelated to overall or cause-specific mortality.

CONCLUSIONS

In the U.S. population, severe hepatic steatosis on ultrasound and liver enzyme elevation were associated with increased liver disease mortality, but were not independently associated with mortality from all causes (except for GGT), CVD, cancer, or diabetes.

Fatty liver indices in the multiethnic United States National Health and Nutrition Examination Survey

BACKGROUND

Validated non-invasive measures of fatty liver are needed that can be applied across populations and over time. A fatty liver index (FLI) including body mass index, waist circumference, triglycerides and gamma glutamyltransferase (GGT) activity was developed in an Italian municipality, but has not been validated widely or examined in a multiethnic population.

AIMS

We evaluated this FLI in the multiethnic U.S. National Health and Nutrition Examination Survey (NHANES) and also to explore whether an improved index for the U.S. population (US FLI) could be derived. The US FLI would then used to examine U.S. time trends in fatty liver prevalence.

METHODS

We studied 5869 fasted, viral hepatitis negative adult participants with abdominal ultrasound data on fatty liver in the 1988-1994 NHANES. Time trend analyses included 21 712 NHANES 1988-1994 and 1999-2012 participants.

RESULTS

The prevalence of fatty liver was 20%. For the FLI, the area under the receiver operating characteristic curve [AUC; 95% confidence interval (CI)] was 0.78 (0.74-0.81). The US FLI included age, race-ethnicity, waist circumference, GGT activity, fasting insulin and fasting glucose and had an AUC (95% CI) of 0.80 (0.77-0.83). Defining fatty liver as a US FLI ≥ 30, the prevalence increased from 18% in 1988-1991 to 29% in 1999-2000 to 31% in 2011-2012.

CONCLUSIONS

For predicting fatty liver, the US FLI was a modest improvement over the FLI in the multiethnic U.S. population. Using this measure, the fatty liver prevalence in the U.S. population increased substantially over two decades.

Relationship of hepatitis C virus infection with diabetes in the U.S. population

An association of hepatitis C virus (HCV) infection with diabetes has been reported in many studies, but few have been population based and applied standard criteria for diabetes diagnosis. We examined this relationship using recent population-based data from the U.S. National Health and Nutrition Examination Survey. Adult participants (15,128) in the 1999-2010 surveys had data on diabetes status and serum HCV antibody (anti-HCV) or HCV RNA. Using American Diabetes Association criteria, diabetes was defined as a health care provider diagnosis, serum hemoglobin A1C (A1C) ≥6.5%, or fasting plasma glucose (FPG) ≥126 mg/dL, prediabetes as A1C 5.7%-<6.5% or FPG 100-<126 mg/dL, and normal glucose as A1C <5.7% and FPG <100 mg/dL. Odds ratios (ORs) for diabetes and prediabetes, comparing persons with HCV infection to those without, were adjusted for demographics, BMI, C-reactive protein, smoking, drinking, and blood transfusion before 1992. Among participants without diabetes, we compared mean insulin resistance (IR), estimated using homeostasis model assessment (HOMA-IR), by HCV status. The overall prevalence of anti-HCV+ was 1.7%, of HCV RNA(+) 1.1%, of diabetes 10.5%, and of prediabetes 32.8%. The prevalence of diabetes and prediabetes did not differ by HCV status. In multivariate-adjusted analysis, diabetes remained unassociated with anti-HCV (OR, 1.0; 95% confidence interval [CI]: 0.6-1.7) or with HCV RNA (OR, 1.1; 95% CI: 0.6-1.9). In contrast, elevated alanine aminotransferase and gamma glutamyltransferase activities were associated with diabetes regardless of HCV status. HOMA-IR was not associated with HCV markers in unadjusted or multivariate-adjusted analyses (P > 0.05).

CONCLUSION

In the U.S. population, HCV was not associated with diabetes or with IR among persons with normal glucose. Previously reported relationships of HCV with diabetes were possibly attributable to the effect of elevated liver enzymes.

The association of low serum alanine aminotransferase activity with mortality in the US population

Elevated alanine aminotransferase (ALT) activity, an important marker of liver injury, has been associated inconsistently with higher mortality. We evaluated whether persons with nonelevated ALT levels are the most appropriate comparison group by examining the relationships of low ALT with mortality and body composition in the US National Health and Nutrition Examination Survey (NHANES). In NHANES 1988-1994, the mortality risk of persons in ALT deciles 1, 2, 3, and 10 was compared with that of persons in deciles 4-9 (mortality was relatively flat across these deciles) over an 18-year period (through 2006) among 14,950 viral-hepatitis-negative adults. In NHANES 1999-2006, low ALT was evaluated in association with dual-energy x-ray absorptiometry body composition measures among 15,028 adults. Multivariate-adjusted mortality was higher for decile 1 (hazard ratio (HR) = 1.42, 95% confidence interval (CI): 1.24, 1.63), decile 2 (HR = 1.27, 95% CI: 1.06, 1.53), and decile 3 (HR = 1.25, 95% CI: 1.04, 1.50) and nonsignificantly higher for decile 10 (HR = 1.21, 95% CI: 0.91, 1.61) than for deciles 4-9. Adjusted appendicular lean mass was decreased among the lowest ALT deciles. In the US population, low ALT was associated with higher mortality risk, possibly attributable to decreased appendicular lean mass. For mortality studies of elevated ALT levels, the most appropriate comparison group is persons in the middle range of ALT rather than all persons with nonelevated ALT.

Diurnal variation in serum alanine aminotransferase activity in the US population

GOALS AND BACKGROUND

Serum alanine aminotransferase (ALT) activity has been reported to be greater in the afternoon than the early morning, but data are scarce. We examined diurnal variation of ALT in a national population-based sample.

STUDY

Participants in the 1999 to 2008 US National Health and Nutrition Examination Survey were randomly assigned to morning (AM; n = 4474 adolescents, 11,235 adults) or afternoon/evening (PM; n = 4887 adolescents, 11,735 adults) examinations. We examined ALT distributions graphically and compared both geometric mean ALT and the prevalence of elevated ALT, defined as >31 IU/L for adolescent boys, >24 IU/L for adolescent girls, >43 IU/L for adult men, and >30 IU/L for adult women, between AM and PM examination groups.

RESULTS

The examination groups were similar with the exception in the AM group of a longer fasting time and slightly higher prevalence of diabetes among adolescents and viral hepatitis B among adult women. ALT distributions were similar between examination sessions among the 4 groups. Among adolescents and men, neither mean ALT nor prevalence of abnormal ALT differed by examination group. Among women, mean ALT was statistically significant, but minimally higher in the PM group (19.6 IU/L) than the AM group (19.1 IU/L; P = 0.009). Among 1 subgroup, women with chronic viral hepatitis, there was a higher prevalence of abnormal ALT in the PM group (P = 0.018 in unadjusted analysis). Adjusting for liver injury risk factors had little effect on the difference in mean ALT.

CONCLUSIONS

In general, clinically significant diurnal variation in ALT activity was not found in the US population.

Upper limits of normal for alanine aminotransferase activity in the United States population

Alanine aminotransferase (ALT) is an important test for liver disease, yet there is no generally accepted upper limit of normal (ULN) in the United States. Furthermore, the ability of ALT to differentiate persons with and without liver disease is uncertain. We examined cut-offs for ALT for their ability to discriminate between persons with positive hepatitis C virus (HCV) RNA and those at low risk for liver injury in the U.S. population. Among adult participants in the 1999-2008 U.S. National Health and Nutrition Examination Survey, 259 were positive for serum HCV RNA and 3,747 were at low risk for liver injury (i.e., negative HCV RNA and hepatitis B surface antigen, low alcohol consumption, no evidence of diabetes, and normal body mass index and waist circumference). Serum ALT activity was measured centrally. Maximum correct classification was achieved at ALT = 29 IU/L for men (88% sensitivity, 83% specificity) and 22 IU/L (89% sensitivity, 82% specificity) for women. The cut-off for 95% sensitivity was an ALT = 24 IU/L (70% specificity) for men and 18 IU/L (63% specificity) for women. The cut-off for 95% specificity was ALT = 44 IU/L (64% sensitivity) for men and 32 IU/L (59% sensitivity) for women. The area under the curve was 0.929 for men and 0.915 for women. If the cut-offs with the best correct classification were applied to the entire population, 36.4% of men and 28.3% of women would have had abnormal ALT.

CONCLUSION

ALT discriminates persons infected with HCV from those at low risk of liver disease, but would be considered elevated in a large proportion of the U.S. population.

Gallstone disease is associated with increased mortality in the United States

BACKGROUND & AIMS

Gallstones are common and contribute to morbidity and health care costs, but their effects on mortality are unclear. We examined whether gallstone disease was associated with overall and cause-specific mortalities in a prospective national population-based sample.

METHODS

We analyzed data from 14,228 participants in the third US National Health and Nutrition Examination Survey (20-74 years old) who underwent gallbladder ultrasonography from 1988 to 1994. Gallstone disease was defined as ultrasound-documented gallstones or evidence of cholecystectomy. The underlying cause of death was identified from death certificates collected through 2006 (mean follow-up, 14.3 years). Mortality hazard ratios (HR) were calculated using Cox proportional hazards regression analysis to adjust for multiple demographic and cardiovascular disease risk factors.

RESULTS

The prevalence of gallstones was 7.1% and of cholecystectomy was 5.3%. During a follow-up period of 18 years or more, the cumulative mortality was 16.5% from all causes (2389 deaths), 6.7% from cardiovascular disease (886 deaths), and 4.9% from cancer (651 deaths). Participants with gallstone disease had higher all-cause mortality in age-adjusted (HR = 1.3; 95% confidence interval [CI]: 1.2-1.5) and multivariate-adjusted analysis (HR = 1.3; 95% CI: 1.1-1.5). A similar increase was observed for cardiovascular disease mortality (multivariate-adjusted HR = 1.4; 95% CI: 1.2-1.7), and cancer mortality (multivariate-adjusted HR = 1.3; 95% CI: 0.98-1.8). Individuals with gallstones had a similar increase in risk of death as those with cholecystectomy (multivariate-adjusted HR = 1.1; 95% CI: 0.92-1.4).

CONCLUSIONS

In the US population, persons with gallstone disease have increased mortality overall and mortalities from cardiovascular disease and cancer. This relationship was found for both ultrasound-diagnosed gallstones and cholecystectomy.

Trunk fat is associated with increased serum levels of alanine aminotransferase in the United States

BACKGROUND & AIMS

Liver injury is associated with obesity and related measures, such as body mass index (BMI) and waist circumference. The relationship between liver injury and body composition has not been evaluated in a population-based study.

METHODS

Using data from a US population-based survey, we examined the contributions of body composition, measured by dual-energy x-ray absorptiometry (DXA), to increased serum alanine aminotransferase (ALT) activity among 11,821 adults without viral hepatitis. Trunk fat, extremity fat, trunk lean, and extremity lean mass were divided by height squared and used to categorize subjects into quintiles; logistic regression odds ratios (OR) were calculated for increased ALT.

RESULTS

Increased ALT was associated with higher measures of fat and lean mass (P < .001) after adjustment for alcohol consumption and other liver injury risk factors in separate models for each DXA measure. Trunk fat was associated with increased ALT (P < or = .001) in models also including any 1 of the other 3 measures. Extremity fat was independently inversely associated among women (P < .001). Trunk and extremity lean mass were not independently related to increased ALT. In models that contained all 4 DXA measures, the OR (95% confidence interval [CI]) for increased ALT for the highest, relative to lowest, quintile of trunk fat/height squared was 13.8 (95% CI: 5.4-35.3) for men and 7.8 (95% CI: 3.9-15.8) for women. When BMI, waist circumference, and trunk fat were considered together, only trunk fat remained independently associated with increased ALT.

CONCLUSIONS

Trunk fat is a major body composition determinant of increased ALT, supporting the hypothesis that liver injury can be induced by metabolically active intraabdominal fat.

Elevated serum alanine aminotransferase and gamma-glutamyltransferase and mortality in the United States population

BACKGROUND & AIMS

Elevated serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) activities are markers of liver injury, but may also be associated with other diseases and death. In a prospective, national, population-based sample, we examined whether elevated ALT and GGT were associated with increased risk of all-cause and disease-specific mortality.

METHODS

Death certificate-based 12-year mortality was analyzed among 14,950 adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, who were negative for markers of viral hepatitis B and C. Abnormal ALT was defined as >30 U/L in men or >19 U/L in women, and abnormal GGT as >51 U/L in men or >33 U/L in women.

RESULTS

Cumulative mortality was 13.9% from all causes, including 4.2% from cardiovascular disease, 4.2% from neoplasms, 0.44% from diabetes, and 0.13% from liver disease. In multivariate-adjusted analyses, elevated ALT was not associated with all-cause mortality (hazard ratio [HR], 1.2; 95% confidence interval [CI], 0.88-1.6). ALT elevation was associated with deaths from liver disease (HR, 8.2; 95% CI, 2.1-31.9), but not from cardiovascular disease (HR, 0.90; 95% CI, 0.56-1.4), neoplasms (HR, 1.0; 95% CI, 0.65-1.5), or diabetes (HR, 2.4; 95% CI, 0.65-9.1). All-cause mortality increased with elevated GGT (HR, 1.5; 95% CI, 1.2-1.8), as did mortality from liver disease (HR, 13.0; 95% CI, 2.4-71.5), neoplasms (HR, 1.5; 95% CI, 1.01-2.2), and diabetes (HR, 3.3; 95% CI, 1.4-7.6), but not from cardiovascular disease (HR, 1.3; 95% CI, 0.80-2.0).

CONCLUSIONS

In the US population, elevated GGT was associated with mortality from all causes, liver disease, cancer, and diabetes, while ALT was associated only with liver disease mortality.

Risk factors for inguinal hernia among adults in the US population

The authors examined risk factors for incident inguinal hernia among US adults (5,316 men and 8,136 women) participating in the First National Health and Nutrition Examination Survey (1971-1975) who were followed through 1992-1993 for a hospital (International Classification of Diseases, Ninth Revision, Clinical Modification, code 550) or physician diagnosis of inguinal hernia. Ninety-six percent of the baseline cohort was recontacted, with a median follow-up of 18.2 years (range, 0.02-22.1 years). Because the cumulative incidence of inguinal hernia was higher among men (13.9%) than among women (2.1%), more detailed analyses were conducted in men. Among men in multivariate analysis, a higher incidence (p < 0.05) of inguinal hernia was associated with an age of 40-59 years (hazard ratio (HR) = 2.2, 95% confidence interval (CI): 1.7, 2.8), an age of 60-74 years (HR = 2.8, 95% CI: 2.2, 3.6), and hiatal hernia (HR = 1.8, 95% CI: 1.2, 2.7), while Black race (HR = 0.58, 95% CI: 0.42, 0.79), being overweight (HR = 0.79, 95% CI: 0.66, 0.95), and obesity (HR = 0.51, 95% CI: 0.36, 0.71) were associated with a lower incidence. Among women, older age, rural residence, greater height, chronic cough, and umbilical hernia were associated with inguinal hernia. In the United States, inguinal hernias are common among men, especially with aging. The lower risk among heavier men was unexpected and bears further study.

Body mass index and serum leptin concentration independently estimate percentage body fat in older adults

BACKGROUND

Because serum concentrations of leptin, a hormone produced by adipocytes, can be relatively reliably and inexpensively measured, it may be considered complementary to, or even a substitute for, body mass index (BMI) as a measure of adiposity.

OBJECTIVE

We examined the ability of BMI and leptin concentrations, separately and together, to estimate total percentage fat in older adults.

DESIGN

Total percentage fat measured by dual-energy X-ray absorptiometry and fasting serum leptin concentrations were measured in 2911 well-functioning 70-79-y-old participants (42% black, 51% women) in the Health, Aging, and Body Composition Study.

RESULTS

Mean (+/-SD) total percentage fat was 29.2 +/-5.0% in men and 40.5 +/- 5.7% in women, and the geometric mean (+/-SD) serum leptin concentration was 5.6 +/- 2.5 ng/mL in the men and 16.4 +/- 2.3 ng/mL in the women. Among men, total percentage fat was strongly associated with both BMI (R(2) = 0.56) and leptin (R(2) = 0.57) in separate linear regression analyses and in a combined linear regression analysis (R(2) = 0.68). Similarly, among women, total percentage fat was associated with both BMI (R(2) = 0.65) and leptin (R(2) = 0.54) separately and in combination (model R(2) = 0.71). Independent relations of BMI and leptin with total percentage fat were also found among both black and white participants. With the population divided into quintiles according to percentage fat, BMI and serum leptin correctly classified 49% of men and 50% of women in the correct quintile.

CONCLUSIONS

Among older adults, total percentage fat was better estimated by using both serum leptin concentrations and BMI than by using either alone. However, their performance does not suggest that they can substitute for more accurate measures.

Joint effects of body weight and alcohol on elevated serum alanine aminotransferase in the United States population

BACKGROUND & AIMS

Both alcohol and obesity are associated with hepatic steatosis. However, little is known about whether the toxicity of alcohol to the liver is influenced by adiposity. We examined the relationship of alcohol drinking and binge drinking with abnormal serum aminotransferase activity in normal weight, overweight, and obese persons in a national, population-based study.

METHODS

Data were analyzed from 13,580 adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, after excluding participants with hepatitis B or C or iron overload. Abnormal aminotransferase levels were defined by using sex-specific cutoffs for ALT and AST. Analyses were adjusted for other liver injury risk factors.

RESULTS

The prevalence of abnormal aminotransferase activity was elevated with consumption of >2 drinks per day or with overweight and obesity. In multivariate analysis, there was no association of alcohol intake with a higher prevalence of elevated aminotransferase levels among normal weight persons. In contrast, among overweight persons, consumption of >2 drinks per day increased the risk of elevated aminotransferase levels, and among the obese, > or = 1 drink per day was associated with a higher risk. Results were similar with elevated ALT alone as the outcome. With elevated AST alone as the outcome, intake of >2 drinks per day increased the risk, even among normal weight persons. Binge drinking was associated with aminotransferase elevation among obese consumers of 1-2 drinks per day.

CONCLUSIONS

In this large, national, population-based study, overweight and obesity increased the risk of alcohol-related abnormal aminotransferase activity.

Coffee and tea consumption are associated with a lower incidence of chronic liver disease in the United States

BACKGROUND & AIMS

Coffee drinking has been suggested to protect against liver injury, but it is uncertain whether this is of clinical significance. We examined the relationship of coffee and tea consumption with the incidence of hospitalization or death from chronic liver disease (CLD).

METHODS

Participants in the population-based, first National Health and Nutrition Examination Survey, 1971-1975, were asked about coffee and tea consumption, which was categorized as <1 cup (mean, 0.2 cups), 1 to 2 cups, and >2 cups per day (mean, 4.0 cups). A second analysis included persons who, in 1982-1984, were asked more detailed questions on coffee and tea drinking. Participants were followed through 1992-1993 for a hospital or death certificate diagnosis of CLD or cirrhosis (ICD-9-CM 571). Hazard rate ratios for CLD according to coffee and tea intake were calculated using Cox proportional hazards analysis.

RESULTS

Among 9849 persons followed for a median of 19.0 years (range, 0.02-22.1), the cumulative incidence of CLD was 1.4%. In multivariate analysis, participants who drank >2 cups per day had less than half the rate of CLD as those who drank <1 cup per day (hazard ratio, 0.43, 95% confidence interval: 0.24-0.78). Protection by coffee and tea was limited to persons at higher risk for liver diseases from heavier alcohol intake, overweight, diabetes, or high iron saturation. Among 9650 participants who provided detailed drink information in 1982-1984, intake of regular ground coffee and of caffeine was associated with lower incidence of CLD.

CONCLUSIONS

Coffee and tea drinking decreases the risk of clinically significant CLD.

Coffee and caffeine consumption reduce the risk of elevated serum alanine aminotransferase activity in the United States

BACKGROUND & AIMS

Based on experimental and epidemiologic studies, we investigated whether coffee and caffeine consumption reduced the risk of elevated alanine aminotransferase (ALT) activity in persons at high risk for liver injury in a national, population-based study.

METHODS

Participants were 5944 adults in the Third US National Health and Nutrition Examination Survey, 1988-1994, with excessive alcohol consumption, viral hepatitis, iron overload, overweight, or impaired glucose metabolism. Liver injury was indicated by abnormal serum ALT activity (>43 U/L).

RESULTS

Elevated ALT activity was found in 8.7% of this high-risk population. In unadjusted analysis, lower ALT activity was associated with increasing consumption of coffee ( P = .001) and caffeine ( P = .001). Multivariate logistic regression analyses showed that the risk of elevated ALT activity declined with increasing intake of coffee ( P for trend = .034) and caffeine ( P < .001). Comparing persons who drank more than 2 cups per day with noncoffee drinkers, the odds ratio was .56 (95% confidence interval, .31-1.0). Comparing persons in the highest caffeine quintile with the lowest, the odds ratio was .31 (95% confidence interval, .16-.61). These relationships were consistent across subgroups at risk for liver injury and were relatively unchanged when analyses included the entire population or when limited to persons without impaired liver function or right upper quadrant pain. Fasting insulin concentrations did not mediate the effects.

CONCLUSIONS

In this large, national, population-based study, among persons at high risk for liver injury, consumption of coffee and especially caffeine was associated with lower risk of elevated ALT activity.

Serum leptin concentrations and body adipose measures in older black and white adults

BACKGROUND

Among US adults, serum leptin concentrations are higher in women than in men and are higher in blacks than in whites independent of anthropometric measures of body fatness.

OBJECTIVE

Using radiographic measures of body fat, we determined the best correlates of leptin and whether adiposity can explain sex and race differences in leptin concentrations in older adults.

DESIGN

This was a cross-sectional analysis of fasting serum leptin concentrations and body fat measured by dual-energy X-ray absorptiometry (DXA), abdominal computed tomography, and standard anthropometry in 3026 well-functioning 70-79-y-old participants (42% black, 51% women) of the Health, Aging, and Body Composition Study.

RESULTS

Geometric mean (+/-SE) leptin concentrations (ng/mL) were higher in the women than in the men (16.5 +/- 0.3 and 5.7 +/- 0.1, respectively) and in the black women than in the white women (20.2 +/- 0.6 and 13.9 +/- 0.4, respectively), but did not differ significantly between the white and black men (5.8 +/- 0.2 and 5.5 +/- 0.2, respectively). Percentage fat estimated from DXA showed the highest correlation with leptin (R(2) = 0.56 for both sexes). Addition of abdominal visceral fat minimally increased the correlation. In the multivariate analysis, the association with sex was eliminated after adjustment for percentage fat and visceral fat in both whites (P = 0.051) and blacks (P = 0.34). Among women, higher leptin concentrations in blacks remained after adjustment for percentage fat and visceral fat (mean race difference = 4.95 ng/mL; P < 0.001). Among men, an association with black race emerged after adjustment for these factors (mean race difference = 1.42 ng/mL; P < 0.001).

CONCLUSIONS

Among older adults, higher serum leptin concentrations in women are explained by a greater percentage of body fat. Higher leptin concentrations in blacks are not explained by percentage of body fat.

Epidemiology of nonalcoholic fatty liver

Nonalcoholic fatty liver (NAFL) is increasingly recognized as an important and common public health problem that can lead to cirrhosis and hepatic failure. Because it is often asymptomatic,many people may not know that they have it. NAFL is closely linked to obesity, which in the United States and other developed countries is becoming more common. Consequently, the proportion of the population affected by NAFL will likely increase. Despite the growing importance of this condition, knowledge of the epidemiology of NAFL is limited by the lack of an accurate,noninvasive measure for use in screening of the general population. This article reviews information available from studies with relatively unselected samples with regard to prevalence, demographics,and risk factors for NAFL.

Detection of alcohol use disorders in general hospital admissions in the United States

BACKGROUND

Previous studies in which research-based assessment for alcohol problems at admission was compared with physician diagnoses indicated that many alcohol diagnoses in hospitalized patients were missed. We estimated the extent to which hospital records documented detection of alcohol abuse or dependence and other alcohol-related problems in a national sample of hospital admissions having a research-based diagnosis of alcohol use disorder ("interview-positive admissions"). We also estimated rates of inpatient alcohol intervention and referral for treatment.

METHODS

A complex, multistage, probability sample was designed to represent nonmaternity, acute-care admissions to nonfederal, short-stay, general hospitals in the contiguous United States. The study included 2040 admissions, 1613 male and 427 female. Research-based diagnoses of current (ie, past 12 months) Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition alcohol use disorder were derived from a structured, computer-assisted, personal interview containing the Alcohol Use Disorders and Associated Disabilities Interview Schedule. Information on detection, inpatient intervention, and treatment referral were obtained via retrospective analysis of closed hospital records covering the index visit.

RESULTS

Record-documented diagnoses of alcohol-related problems were found in 40% to 42% of interview-positive admissions. Inpatient intervention rate was estimated at 21% for interview-positive admissions, and treatment referral rate, 24%. For detected interview-positive admissions, estimated rates of intervention and referral were 50% and 53%, respectively.

CONCLUSIONS

Estimated rates of detection, inpatient intervention, and treatment referral of alcohol use disorders in hospital admissions were low. Current-drinking hospital admissions should be screened for alcohol problems as part of the admission routine, with further professional evaluation, intervention, and treatment referral as indicated.

Gastric function in the elderly: effects on absorption of ketoconazole

The authors studied effects of age-related changes in gastric function on absorption of ketoconazole. Eighteen men and women age 65 years or older swallowed 200 mg ketoconazole on two occasions, once as tablets with water and once as tablets crushed in acidic juice. The sequence was randomly determined. Gastric pH was measured by radiotelemetry and gastric emptying rate by radiolabeled technetium with a gamma camera. Plasma ketoconazole was assayed by high-performance liquid chromatography (HPLC). Subjects with gastric pH less than or equal to 4.5 absorbed ketoconazole equally well from intact tablets and tablets crushed in acid. When pH was 5.0 or higher, ketoconazole was absorbed well from acid-crushed tablets but not from intact tablets. Gastric emptying was shown to be rapid in all subjects. Since the prevalence of such hypoacivity is approximately 5% in the elderly, and other parameters of gastric function are usually normal, impaired absorption of drugs such as ketoconazole should be uncommon with normal aging.

Relation of elevated serum alanine aminotransferase activity with iron and antioxidant levels in the United States

BACKGROUND & AIMS

Oxidative stress is thought to play a role in liver injury. Hepatic iron may promote liver injury, whereas antioxidant vitamins and minerals may inhibit it, but few clinical studies have examined such relationships. We analyzed the associations of serum iron measures and antioxidant concentrations with abnormal serum alanine transaminase (ALT) activity in a large, national, population-based study.

METHODS

A total of 13,605 adult participants in the third U.S. National Health and Nutrition Examination Survey (NHANES III), 1988-1994, underwent phlebotomy. Exclusions included excessive alcohol consumption, hepatitis B and C, and iron overload.

RESULTS

Elevated ALT levels were found in 3.1% of the population. In univariate analysis, factors associated with abnormal ALT levels (P < 0.05) included higher transferrin saturation and iron and selenium concentrations, and lower vitamin C, alpha and beta carotene, and lutein/zeaxanthin concentrations. In multivariate logistic regression analyses, elevated ALT level was associated positively with increasing deciles of transferrin saturation (odds ratio [OR] per decile, 1.10; 95% confidence interval [CI], 1.03-1.18) and iron concentration (OR, 1.13; 95% CI, 1.06-1.21). Abnormal ALT level was associated negatively with increasing deciles of alpha carotene (OR, 0.82; 95% CI, 0.72-0.94), beta carotene (OR, 0.91; 95% CI, 0.86-0.96), beta cryptoxanthin (OR, 0.91; 95% CI, 0.84-0.99), lutein/zeaxanthin (OR, 0.90; 95% CI, 0.84-0.96), and a variable combining the 5 carotenoid measures (OR, 0.89; 95% CI, 0.83-0.95). Vitamin C was associated inversely, but only at the highest concentrations.

CONCLUSIONS

In this large, national, population-based study, the risk for apparent liver injury was associated with increased iron and decreased antioxidants, particularly carotenoids.

Determinants of the association of overweight with elevated serum alanine aminotransferase activity in the United States

BACKGROUND & AIMS

In the absence of other causes, overweight and obesity increase the risk of liver disease. We examined whether central adiposity and metabolic markers explain the association of body mass index (BMI as kg/m(2)) with abnormal serum alanine aminotransferase (ALT) activity in a national, population-based study.

METHODS

Adult participants (5724) in the third U.S. National Health and Nutrition Examination Survey (1988-1994) underwent anthropometric measures and phlebotomy after an overnight fast. Participants with excessive alcohol consumption, hepatitis B, hepatitis C, iron overload, or known diabetes were excluded.

RESULTS

Elevated ALT levels were found in 2.8% of the population. In univariate analysis, factors associated with elevated ALT levels (P < 0.05) included younger age, male sex, Mexican-American ethnicity, and higher BMI, waist-to-hip circumference ratio (WHR), and fasting serum leptin, triglyceride, insulin, and glucose concentrations. The proportion of elevated ALT activity due to overweight and obesity (BMI > or =25 kg/m(2)) was 65%. In multivariate logistic regression analysis, control for WHR, demographic factors, and glucose concentration diminished but did not eliminate the association of higher BMI with elevated ALT activity. After adding leptin and insulin concentrations, abnormal ALT activity was most strongly associated with higher WHR (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.12-1.56) and leptin (OR, 1.12; 95% CI, 1.01-1.24) and insulin (OR, 1.27; 95% CI, 1.01-1.60) concentrations, whereas BMI was not independently related.

CONCLUSIONS

In this large, national, population-based study, central adiposity, hyperleptinemia, and hyperinsulinemia were the major determinants of the association of overweight with elevated serum ALT activity.

Relationship of serum leptin concentration with bone mineral density in the United States population

Overweight is associated with both higher bone mineral density (BMD) and higher serum leptin concentrations. In humans, little is known about the relationship of leptin concentration and bone density. We studied this relationship in a large, national population-based sample. Participants included 5815 adults in the Third U.S. National Health and Nutrition Examination Survey (NHANES III; 1988-1994) who underwent DXA of the proximal femur and measurement of fasting serum leptin. Mean +/- SE BMD (gm/cm2) of the total hip was 1.01 +/- 0.005 in men, 0.94 +/- 0.004 in premenopausal women, and 0.78 +/- 0.007 in postmenopausal women. Bone density increased with increasing leptin concentration in men (p = 0.003), premenopausal women (p < 0.001), and postmenopausal women (p < 0.001). However, after adjusting for body mass index (BMI) and other bone density-related factors, an inverse association emerged in men (p < 0.001), being most evident among men < 60 years old. There was no association of leptin and BMD in premenopausal women (p = 0.66) or postmenopausal women (p = 0.69) in multivariate analysis. Controlling for leptin had no effect on the strong positive association of BMI and BMD in either men or women. Serum leptin concentration did not appear to affect directly BMD. If present, the association appeared to be limited to younger men who are at lower risk of osteoporosis.

Relationship of serum leptin concentration and other measures of adiposity with gallbladder disease

Obesity increases the risk of gallstones, especially in women. Most gallbladder disease studies have used body mass index (BMI) as a measure of overall adiposity, although BMI does not distinguish between fat and lean body mass. Central adiposity may also increase gallstone risk, although this is less well studied. Leptin is a peptide whose serum concentration is highly correlated with total body fat mass. We examined the relationship of gallbladder disease with anthropometric measures and serum leptin concentration in a large, national, population-based study. A total of 13,962 adult participants in the Third National Health and Nutrition Examination Survey underwent gallbladder ultrasonography and anthropometric measurements of BMI, body circumferences, and skinfold thicknesses, and a random subgroup of 5,568 had measures of fasting serum leptin concentrations. Gallstone-associated gallbladder disease was defined as ultrasound-documented gallstones or evidence of cholecystectomy. When controlling for BMI and other gallbladder disease risk factors in multivariate analysis, a test for trend for increasing waist-to-hip circumference ratio and risk of gallbladder disease was statistically significant among women (P =.043) and men (P =.007). BMI remained strongly associated with gallbladder disease among women (P <.001), but was unrelated among men (P =.46). Leptin concentration was associated with gallbladder disease in both sexes (P <.001), but not after controlling for BMI and waist-to-hip circumference in either women (P =.29) or men (P =.65). In conclusion, waist-to-hip circumference ratio was related to gallbladder disease among women and men. Serum leptin concentration was not a better predictor of gallbladder disease than anthropometry.

Hospitalization with respiratory disease following hiatal hernia and reflux esophagitis in a prospective, population-based study

PURPOSE

Hiatal hernia and reflux esophagitis have been associated with respiratory manifestations, though the temporal sequence of this relationship is uncertain. This study examined prospectively the relationship of hiatal hernia and reflux esophagitis with respiratory outcomes in a representative sample of the United States population.

METHODS

6928 participants in the first National Health and Nutrition Examination Survey, a population-based sample initially examined in 1971-1975, who were hospitalized during follow-up through 1992-1993 composed the study population. The relationship between hiatal hernia and reflux esophagitis hospitalization and a subsequent hospitalization with respiratory outcomes was measured in persons free of respiratory disease at baseline and at first hospitalization.

RESULTS

Multivariable survival analysis showed higher rates of hospitalization with any respiratory diagnosis [rate ratio (RR) = 1.4, 95% confidence interval (CI) 1.2-1.7] in persons with preceding hiatal hernia or reflux esophagitis hospitalization. Individually, rate ratios of pharyngitis (RR = 5.6, CI 2.0-15.7), tonsillitis (RR = 8.0, CI 2.5-25.8), bronchitis (RR = 1.8, CI 1.2-2.7), pneumonia (RR = 1.3, CI 1.0-1.7), emphysema (RR = 2.9, CI 1.5-5.5), asthma (RR = 2.1, CI 1.1-4.2), bronchiectasis (RR = 6.2, CI 1.1-34.3), and empyema or abscess (RR = 7.4, CI 1.3-42.3) were all higher following hiatal hernia and reflux esophagitis. Rate ratios were similar when reflux esophagitis and hiatal hernia were examined separately.

CONCLUSIONS

A prior hiatal hernia or reflux esophagitis hospitalization increased risk of respiratory disease hospitalization.

Leptin concentrations in the United States: relations with demographic and anthropometric measures

BACKGROUND

Leptin is a peptide that is strongly correlated with adiposity and is a potential determinant of obesity and its complications.

OBJECTIVE

Leptin concentrations from a representative sample of the US population were examined in relation to demographic and anthropometric measures.

DESIGN

Fasting serum leptin concentrations were measured in 6303 women and men aged > or =20 y in the third National Health and Nutrition Examination Survey. Anthropometric measures included body mass index, 4 skinfold thicknesses, and 4 body circumferences. Ethnic groups included non-Hispanic whites and blacks and Mexican Americans.

RESULTS

The mean serum leptin concentration was much higher in women (12.7 microg/L) than in men (4.6 microg/L). In a multivariate analysis, leptin concentrations were associated with the sum of 4 skinfold thicknesses, waist and hip circumferences, ethnicity, and age. These measures explained most of the variance in leptin concentrations in women (R2 = 0.69) and in men (R2 = 0.67). Triceps skinfold thickness, when substituted for the sum of skinfold thicknesses, performed nearly as well in women (R2 = 0.68) and men (R2 = 0.67). Leptin concentrations were slightly but significantly higher in non-Hispanic blacks than in non-Hispanic whites of both sexes when these anthropometric measures and age were controlled for; Mexican Americans had concentrations that were intermediate compared with the concentrations of non-Hispanic whites and blacks.

CONCLUSIONS

In this large, representative sample of the US population, demographic and anthropometric measures predicted serum leptin concentrations in women and men.

Relationship of iron-deficiency anemia with esophagitis and hiatal hernia: hospital findings from a prospective, population-based study

OBJECTIVE

Iron-deficiency anemia is sometimes attributed to esophagitis and hiatal hernia; however, because these GI conditions are so common, such an association could be coincidental. We examined prospectively whether esophagitis and hiatal hernia increased the risk of iron-deficiency anemia in a national, population-based study.

METHODS

The study population comprised 5069 adult participants in the first National Health and Nutrition Examination Survey, who were free of GI hemorrhage and anemia at baseline examination in 1971-1975 and who were hospitalized at some point during nearly 20 yr of follow-up. Rates of hospitalization with iron-deficiency or unspecified anemia were compared between patients with a hospital diagnosis of esophagitis or hiatal hernia and those who had not yet had a diagnosis of these disorders. Adjusted rate ratios were calculated using time-dependent, multivariable, proportional hazards analysis.

RESULTS

During follow-up, 59 patients were hospitalized with esophagitis alone, 140 with hiatal hernia alone, and 70 with both diagnoses. A total of 102 participants were hospitalized with iron-deficiency anemia and 256 with unspecified anemia. Compared to those without a diagnosis of esophagitis or hiatal hernia, patients with a diagnosis of hiatal hernia had higher rates of subsequent hospitalization with iron-deficiency anemia. The hazard rate ratio (HRR) for hiatal hernia was 2.9 (95% confidence interval, 1.5-5.5). A trend was found for esophagitis with a HRR of 2.2 (95% confidence interval, 0.79-6.0). Results were similar with unspecified anemia as the outcome.

CONCLUSIONS

Hiatal hernia should be considered as a possible cause of iron-deficiency anemia. The relationship of esophagitis with iron-deficiency anemia requires further study.

Association of coffee consumption with gallbladder disease

Coffee consumption was recently shown to protect against symptomatic gallbladder disease in men. The authors examined the relation of ultrasound-documented gallbladder disease with coffee drinking in 13,938 adult participants in the Third National Health and Nutrition Examination Survey, 1988-1994. The prevalence of total gallbladder disease was unrelated to coffee consumption in either men or women. However, among women a decreased prevalence of previously diagnosed gallbladder disease was found with increasing coffee drinking (p = 0.027). These findings do not support a protective effect of coffee consumption on total gallbladder disease, although coffee may decrease the risk of symptomatic gallstones in women.

Association of diabetes, serum insulin, and C-peptide with gallbladder disease

An inconsistent association has been found between gallbladder disease and diabetes mellitus. We hypothesized that insulin resistance rather than diabetes status may be a primary factor involved in gallstone formation. A total of 5,653 adult participants in the third United States National Health and Nutrition Examination Survey without known diabetes underwent gallbladder ultrasonography and phlebotomy after an overnight fast for measurement of serum insulin, C-peptide, and glucose. Gallbladder disease was defined as ultrasound-documented gallstones or evidence of cholecystectomy. Subjects were characterized as having normal fasting glucose (<110 mg/dL), impaired fasting glucose (110 to <126 mg/dL), or undiagnosed diabetes (>/=126 mg/dL). After controlling for other known gallbladder disease risk factors, among women, undiagnosed diabetes was associated with increased risk of gallbladder disease (prevalence ratio [PR] = 1.91, 95% confidence interval [CI] = 1.29-2. 83); whereas impaired fasting glucose was unassociated. Gallbladder disease risk in women increased with levels of fasting insulin (PR = 1.63, 95% CI = 1.11-2.40) and C-peptide (PR = 2.07, 95% CI = 1.32-3. 25) comparing highest to lowest quintiles. However, the association of gallbladder disease with undiagnosed diabetes was not diminished when the model included fasting insulin (PR = 1.85, 95% CI = 1.24-2. 77). In men, there was a statistically nonsignificant association with undiagnosed diabetes (PR = 2.11, 95% CI = 0.76-5.85), but no association of gallbladder disease with insulin or C-peptide. Among women higher fasting serum insulin levels increased the risk of gallbladder disease, but did not account for the increased risk in persons with diabetes.

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization: the NHANES I Epidemiologic Followup Study. First National Health and Nutrition Examination Survey

PURPOSE

Gastroesophageal reflux disease is an important and increasingly common condition. Both overweight and high fat food consumption have been implicated as causes of reflux disease. We examined the relationship of overweight, high dietary fat intake, and other factors with reflux disease hospitalization.

METHODS

We studied participants in the first National Health and Nutrition Examination Survey, a population-based sample examined in 1971-75 and followed through 1992-93. Persons with a physician-diagnosed hiatal hernia at baseline or reflux disease hospitalization within the first five years of study were excluded. A second analysis included follow-up of 9851 participants free of reflux disease in 1982-84. Ninety-six percent of the baseline cohort were recontacted. Reflux disease cases were persons hospitalized with a diagnosis of esophagitis or uncomplicated hiatal hernia. Hazard rate ratios for reflux disease hospitalization according to body mass index (BMI) (kg/m2), total daily servings of high fat foods and other factors were calculated using Cox proportional hazards analysis.

RESULTS

A total of 12,349 persons were followed for a median of 18.5 years (range 5.0-22.1). Cumulative incidence of reflux disease hospitalization was 5.2% at 20 years. Multivariate survival analysis revealed higher reflux disease hospitalization rates with higher BMI (5 kg/m2) [hazard ratio (HR) = 1.22, 95% confidence interval (CI) = 1.13-1.32]. No relationship was found between higher fat intake and reflux disease hospitalization. Other factors associated with reflux disease hospitalization included age, low recreational activity, and history of doctor-diagnosed arthritis.

CONCLUSIONS

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization.

Injury and death associated with hospital bed side-rails: reports to the US Food and Drug Administration from 1985 to 1995

OBJECTIVES

Hospital bed side-rails, while intended for patient protection, can contribute to injury and death. Reports to the Food and Drug Administration (FDA) of hospital bed side-rail entrapment have increased. In this paper entrapment cases are reviewed and the population potentially at risk identified.

METHODS

FDA's database was searched for events involving hospital beds from January 1985 to August 1995 and entrapment cases were identified.

RESULTS

Of 111 entrapments, 65% were associated with death and 23% with injury.

CONCLUSIONS

Advanced age, female sex, low body weight, and cognitive impairment may be associated with increased risk. Preventive measures are detailed.

Bladder cancer and drinking water: a population-based case-control study in Washington County, Maryland (United States)

A population-based case-control study was conducted in Washington County, Maryland (United States) to explore the association between incident bladder cancer and exposure to drinking water from chlorinated surface sources. Cancer cases were White residents, enumerated in a 1975 county census and reported to the Washington County Cancer Registry (n = 294) between 1975 and 1992. White controls, frequency matched by age (+/- 5 years) and gender, were selected randomly from the census (n = 2,326). Households receiving municipal water, which generally derived from chlorinated surface waters, were treated as having 'high exposure' and all others, as 'low exposure.' Duration of exposure to type of drinking water was based on length of residence in the census household prior to 1975. Odds ratios (OR) were calculated using logistic regression methods, adjusting for age, gender, tobacco use, and urbanicity. Bladder cancer risk was associated weakly in the general population with duration of exposure to municipal water. The association was limited to those who had smoked cigarettes. In ever-smokers compared with never-smokers with low exposure, the adjusted ORs for bladder cancer risk with increasing exposure were 1.3, 1.4, 1.4, 1.7, 2.2, 2.8, respectively, for 0, 1-10, 11-20, 21-30, 31-40, > 40 years' exposure duration. The ORs in smokers were not diminished after adjusting for smoking history and intensity.

Gastric acidity in older adults

CONTEXT

Early studies suggested that gastric acidity declines as people age. However, sequelae of achlorhydria are uncommon in older people, making this conventional wisdom unlikely.

OBJECTIVE

To ascertain the prevalence of basal gastric acidity and atrophic gastritis (indicated by serum pepsinogen ratio) in older adults.

DESIGN

Cross-sectional study in a volunteer sample.

SETTING

Retirement communities in suburbs of Kansas City, Mo.

SUBJECTS

A total of 248 white male and female volunteers aged 65 years or older living independently.

MAIN OUTCOME MEASURES

Presence of basal unstimulated gastric acid was evaluated noninvasively by having subjects swallow quininium resin. Gastric acid with a pH lower than 3.5 releases quinine, which is then absorbed and excreted into urine. Atrophic gastritis was defined as a ratio of serum pepsinogen I/pepsinogen II of less than 2.9.

RESULTS

Basal unstimulated gastric content was acidic (pH <3.5) in 208 (84%) of 248 elderly subjects. On retesting 66 subjects (35 normals and 31 hyposecretors), 28 (80%) of 35 had pH less than 3.5 both times, and 22 (71%) of 31 had pH of 3.5 or higher twice; in the remaining 16 subjects, low vs high gastric pH changed between tests. Weighted population prevalence estimates in this sample were 67% for consistent acid secretion, 22% for intermittent secretion, and 11% for consistent gastric pH higher than 3.5. Whereas 14 (67%) of 21 consistent hyposecretors had serum pepsinogen ratios of less than 2.9, indicating atrophic gastritis, only 2 (5%) of 44 consistent or intermittent secretors of acid had ratios in this range (P<.001).

CONCLUSIONS

In contrast to what is commonly stated, nearly 90% of elderly people in this study were able to acidify gastric contents, even in the basal, unstimulated state. Of those who were consistent hyposecretors of acid, most had serum markers of atrophic gastritis.