Prevalence and incidence of chronic fatigue syndrome in Wichita,Kansas

BACKGROUND: Chronic fatigue syndrome (CFS) is a debilitating illness with no known cause or effective therapy. Population-based epidemiologic data on CFS prevalence and incidence are critical to put CFS in a realistic context for public health officials and others responsible for allocating resources and for practicing physicians when examining and caring for patients. METHODS: We conducted a random digit-dialing survey and clinical examination to estimate the prevalence of CFS in the general population of Wichita, Kan, and a 1-year follow-up telephone interview and clinical examination to estimate the incidence of CFS. The survey included 33 997 households representing 90 316 residents. This report focuses on 7162 respondents aged 18 to 69 years. Fatigued (n = 3528) and randomly selected nonfatigued (n = 3634) respondents completed telephone questionnaires concerning fatigue, other symptoms, and medical history. The clinical examination included the Diagnostic Interview Schedule for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, laboratory testing, and a physical examination. RESULTS: The overall weighted point prevalence of CFS, adjusted for nonresponse, was 235 per 100,000 persons (95% confidence interval, 142-327 per 100,000 persons). The prevalence of CFS was higher among women, 373 per 100,000 persons (95% confidence interval, 210-536 per 100,000 persons), than among men, 83 per 100,000 persons (95% confidence interval, 15-150 per 100,000 persons). Among subjects nonfatigued and fatigued for less than 6 months, the 1-year incidence of CFS was 180 per 100,000 persons (95% confidence interval, 0-466 per 100,000 persons). CONCLUSIONS: Chronic fatigue syndrome constitutes a major public health problem. Longitudinal follow-up of this cohort will be used to further evaluate the natural history of this illness.     

Metabolic syndrome and risk of acute coronary syndromes in patients younger than 45 years of age

OBJECTIVE: There is a paucity of data with regard to the association of the metabolic syndrome with cardiovascular risk in young adults. We investigated the association of the metabolic syndrome with acute coronary syndrome in adults aged 45 years or younger. PATIENTS AND METHODS: A total of 136 consecutive patients (128 men and eight women; mean age, 41.2+/-3.7 years) presenting with a first-ever acute coronary syndrome, and 136 age-matched and sex-matched controls were evaluated. The diagnosis of the metabolic syndrome was established according to the Adult Treatment Panel III criteria. RESULTS: The prevalence of the metabolic syndrome was significantly higher in the patients' group compared with the control group (40.4 versus 23.5%; P=0.003). Multivariate logistic regression analysis showed that smoking, positive family history of premature coronary artery disease, and the metabolic syndrome were associated with odds ratios 4.46 (95% confidence interval, 2.30-8.66; P<0.001), 3.11 (95% confidence interval, 1.71-5.66; P<0.001), and 1.97 (95% confidence interval, 1.08-3.56; P=0.02) higher odds, respectively, of having an acute coronary syndrome, after taking into account the matching for age and sex and controlling for potential confounders. Moreover, a 10-mg/dl increase in total cholesterol was associated with 1.06 higher odds of having an acute coronary syndrome. Analysis of interaction showed that smoking and a positive family history of premature coronary artery disease in young individuals with metabolic syndrome had an incremental effect on the odds of suffering an acute coronary syndrome (odds ratio, 7.12; 95% confidence interval, 2.42-20.96; P<0.001). CONCLUSION: The metabolic syndrome is highly associated with acute coronary syndrome in patients younger than 45 years of age, indicating the need for early and intensive preventive measures.     

Metabolic syndrome increases the risk of primary liver cancer in the United States: a study in the SEER-Medicare database

Incidence rates of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) have increased in the United States. Metabolic syndrome is recognized as a risk factor for HCC and a postulated one for ICC. The magnitude of risk, however, has not been investigated on a population level in the United States. We therefore examined the association between metabolic syndrome and the development of these cancers. All persons diagnosed with HCC and ICC between 1993 and 2005 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. For comparison, a 5% sample of individuals residing in the same regions as the SEER registries of the cases was selected. The prevalence of metabolic syndrome as defined by the U.S. National Cholesterol Education Program Adult Treatment Panel III criteria, and other risk factors for HCC (hepatitis B virus, hepatitis C virus, alcoholic liver disease, liver cirrhosis, biliary cirrhosis, hemochromatosis, Wilson's disease) and ICC (biliary cirrhosis, cholangitis, cholelithiasis, choledochal cysts, hepatitis B virus, hepatitis C virus, alcoholic liver disease, cirrhosis, inflammatory bowel disease) were compared among persons who developed cancer and those who did not. Logistic regression was used to calculate odds ratios and 95% confidence intervals. The inclusion criteria were met by 3649 HCC cases, 743 ICC cases, and 195,953 comparison persons. Metabolic syndrome was significantly more common among persons who developed HCC (37.1%) and ICC (29.7%) than the comparison group (17.1%, P<0.0001). In adjusted multiple logistic regression analyses, metabolic syndrome remained significantly associated with increased risk of HCC (odds ratio=2.13; 95% confidence interval=1.96-2.31, P<0.0001) and ICC (odds ratio=1.56; 95% confidence interval=1.32-1.83, P<0.0001). CONCLUSION: Metabolic syndrome is a significant risk factor for development of HCC and ICC in the general U.S. population.     

A community-based study of chronic fatigue syndrome.

BACKGROUND: Most previous estimates of the prevalence of chronic fatigue syndrome (CFS) have derived largely from treated populations, and have been biased by differential access to health care treatment linked with sex, ethnic identification, and socioeconomic status. OBJECTIVE: To assess the point prevalence of CFS in an ethnically diverse random community sample. DESIGN AND PARTICIPANTS: A sample of 28,673 adults in Chicago, Ill, was screened by telephone, and those with CFS-like symptoms were medically evaluated. MAIN OUTCOME MEASURES AND ANALYSES: Self-report questionnaires, psychiatric evaluations, and complete medical examinations with laboratory testing were used to diagnose patients with CFS. Univariate and multivariate statistical techniques were used to delineate the overall rate of CFS in this population, and its relative prevalence was subcategorized by sex, ethnic identification, age, and socioeconomic status. RESULTS: There was a 65.1% completion rate for the telephone interviews during the first phase of the study. Findings indicated that CFS occurs in about 0.42% (95% confidence interval, 0.29%-0.56%) of this random community-based sample. The highest levels of CFS were consistently found among women, minority groups, and persons with lower levels of education and occupational status. CONCLUSIONS: Chronic fatigue syndrome is a common chronic health condition, especially for women, occurring across ethnic groups. Earlier findings suggesting that CFS is a syndrome primarily affecting white, middle-class patients were not supported by our findings.     

Factors influencing the diagnosis of chronic fatigue syndrome

BACKGROUND: Most of what is believed about chronic fatigue syndrome (CFS) is based on clinic-based studies. These studies may not reflect CFS cases in the population. METHODS: We used data from a population-based study of CFS to identify factors associated with receiving a CFS diagnosis. Wichita, Kan, residents were screened by random-digit dialing. Eligible individuals completed a telephone interview. Respondents meeting CFS criteria were invited for a clinical evaluation to confirm CFS. We analyzed all persons with confirmed CFS. The main outcomes of this study, prevalence and incidence of CFS, are published elsewhere. Herein, we present an exploratory analysis with previous CFS diagnosis as the outcome, predicted by demographic and symptom characteristics. RESULTS: We confirmed CFS in 90 subjects; 14 (16%) had been previously diagnosed as having CFS. Persons in the middle- vs the higher-income group were more likely to have been diagnosed as having CFS (9 [29%] of 31 subjects vs 3 [8%] of 39 subjects; P = .03), as were those with sudden vs gradual fatigue onset (7 [41%] of 17 subjects vs 4 [6%] of 64 subjects; P < .01), those reporting tender lymph nodes (7 [33%] of 21 subjects vs 7 [10%] of 69 subjects; P = .02), and those reporting a sore throat (6 [35%] of 17 subjects vs 8 [11%] of 73 subjects; P = .02). Only 17 (21%) of 81 subjects had sudden fatigue onset, and tender lymph nodes (reported in 21 [23%] of 90 subjects) and a sore throat (reported in 17 [19%] of 90 subjects) were the least common symptoms. CONCLUSION: Most cases of CFS in the population are unrecognized by the medical community; persons diagnosed as having CFS may be different from persons with CFS in the general population.     

The metabolic syndrome is associated with reduced central serotonergic responsivity in healthy community volunteers

CONTEXT: The pathobiology of the metabolic syndrome remains unclear. The central nervous system is likely to be involved via regulation of eating, physical activity, blood pressure, and metabolism. OBJECTIVE: The objective of this study was to test the hypothesis that low central serotonergic activity is associated with the metabolic syndrome. DESIGN, SETTING, PARTICIPANTS: This was a cross-sectional study of 345 healthy community volunteers, aged 30-55 yr, not taking medications for hypertension, lipid disorders, or diabetes. OUTCOME MEASURES: Central serotonergic responsivity was assessed with the iv citalopram challenge test. The serum prolactin area under the curve (AUC) over 150 min was calculated, and all analyses were adjusted for age, sex, plasma citalopram concentration, and baseline prolactin. The metabolic syndrome was defined according to the National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) criteria. Insulin resistance was estimated by homeostasis model assessment. RESULTS: Compared with other individuals, persons meeting either NCEP or IDF criteria for the metabolic syndrome had lower mean prolactin responses (P < 0.05 for both). Using logistic regression, a decrease in prolactin AUC of 1 sd (-13.6 ng/ml.h) more than doubled the odds of having the metabolic syndrome (NCEP criteria: odds ratio, 2.38; 95% confidence interval, 1.14-4.97; P = 0.02; IDF criteria: odds ratio, 2.80; 95% confidence interval, 1.48-5.30; P = 0.002). Finally, the prolactin AUC was negatively associated with insulin resistance (beta = -0.03, P = 0.02). CONCLUSIONS: Corroborating previous evidence, the metabolic syndrome was associated with diminished brain serotonergic activity as reflected in a comparative blunting of the prolactin response to a selective serotonergic challenge. This association may have implications for the etiology, prevention, and treatment of the metabolic syndrome.     

Polymorphisms in the fatty acid-binding protein 2 and apolipoprotein C-III genes are associated with the metabolic syndrome and dyslipidemia in a South Indian population

The Chennai Urban Population Study investigates a South Indian population with a high prevalence of cardiovascular disease associated with the metabolic syndrome (MS). The Ala54Thr polymorphism in the fatty acid-binding protein 2 (FABP2) gene as well as the T-455C and C-482T polymorphisms in the apolipoprotein C-III (APOC3) gene promoter have been associated with features of the MS in specific populations. This study evaluates in Asian-Indians the association between these polymorphisms with MS and dyslipidemia, defined according to National Cholesterol Education Program Adult Treatment Panel III. Allelic frequencies in 70 controls and 110 patients with diabetes from the Chennai Urban Population Study were 52.9% for FABP2 Thr54, 73.0% for APOC3 -482T, and 80.2% for APOC3 -455C. The polymorphisms were in agreement with Hardy-Weinberg equilibrium. Controls carrying FABP2 Thr54 were more likely to have MS than noncarriers (Fisher's exact test P = 0.031; odds ratio = 6.9 with a 95% confidence interval of 1.1, 43.9). Those carrying at least one polymorphic allele in both genes had a higher likelihood of having MS than wild type (Fisher's exact test P = 0.003; odds ratio = 12.1 with a 95% confidence interval of 1.88, 77.6). Dyslipidemia was associated with the polymorphism as well. The polymorphisms were not associated with MS in patients with diabetes. The association of the polymorphisms with MS and dyslipidemia could contribute to the high cardiovascular disease prevalence in this population.     

Metabolic syndrome in Japanese patients with obstructive sleep apnea syndrome.

We investigated the prevalence of metabolic syndrome in patients with obstructive sleep apnea syndrome (OSAS) referred to a tertiary university-based medical center. A cross-sectional study of patients with a definite diagnosis of OSAS was performed using new diagnostic criteria for metabolic syndrome that were designed for the Japanese population. Clinical features and comorbidities related to metabolic syndrome were compared between 819 patients with OSAS (719 men and 100 women) and 89 control subjects without OSAS. Metabolic syndrome was significantly more common in the patients with OSAS than in the controls (49.5% vs. 22.0% for men, p < 0.01; 32.0% vs. 6.7% for women, p < 0.01). Men with OSAS (apnea-hypopnea index [AHI] > or =5/h) had a higher risk of metabolic syndrome compared with controls (odds ratio [OR]: 3.47; 95% confidence interval [CI]: 1.84-6.53). There was a significantly increased risk of metabolic syndrome in men with moderate OSAS (AHI: 15-29.9/h) (OR: 2.83; 95% CI: 1.42-5.66) and men with severe OSAS (AHI > or =30/h) (OR: 5.09; 95% CI: 2.67-9.71). Women with OSAS (AHI> or =5/h) also had an increased risk of metabolic syndrome (OR: 6.59; 95% CI: 1.47-29.38), and the risk was significantly higher in women with severe OSAS (AHI > or =30/h) (OR 14.00; 95% CI: 2.93-66.82). Risk factors for metabolic syndrome differed by gender: in men, age, body mass index (BMI), and OSAS (AHI > or =15/h) were significantly associated with metabolic syndrome, whereas, in women, BMI was the only risk factor for metabolic syndrome. The increase of metabolic syndrome in Japanese OSAS patients suggests that this patient population is burdened with multiple risk factors for cardiovascular disease.     

Microvascular function, metabolic syndrome, and novel risk factor status in women with cardiac syndrome X

To characterize microvascular function, candidate risk pathways, and metabolic syndrome prevalence in women with cardiac syndrome X, 52 nondiabetic women with angiographically normal epicardial arteries but >1 mm of planar ST depression during exercise testing (patients) and 24 healthy controls of similar age were recruited. In addition to fasting blood samples and anthropometric measurements, forearm cutaneous microvascular function after iontophoresis of acetylcholine and sodium nitroprusside was assessed by laser Doppler imaging. Despite body mass index correction and a larger proportion on statin therapy, patients had high levels of insulin (p=0.016), triglycerides (p=0.018), intercellular adhesion molecule-1 (p=0.021), von Willebrand factor (p=0.005), and leptin (p=0.005) and lower levels of high-density lipoprotein cholesterol (p=0.042) compared with controls. Consistent with these data, 30% of patients but only 8% of controls fulfilled criteria for the metabolic syndrome as defined by the National Cholesterol Education Program (p=0.015). Endothelium-dependent and -independent microvascular functions were markedly impaired in patients (p<0.001), and the odds ratio for cardiac syndrome X was 7.38 (95% confidence interval 2.2 to 24.7) if the acetylcholine response was <8,710 flux units. In conclusion, women with cardiac syndrome X more commonly have metabolic syndrome and related adiposity, metabolic, and inflammatory derangements. They also have significantly impaired skin microvascular function as assessed by laser Doppler imaging, consistent with generalized vascular dysfunction, a finding with potential diagnostic implications.     

Serum 25-hydroxyvitamin D levels and the metabolic syndrome in older persons: a population-based study

Background Recent evidence indicates that a lower plasma level of 25‐hydroxyvitamin D (25 OHD) is associated with a higher risk of the metabolic syndrome. It has not been studied in older people with a high prevalence of vitamin D insufficiency. Objective This study investigates the association between vitamin D status and the metabolic syndrome in community‐dwelling older persons in the Netherlands. Design and patients The study is part of the Longitudinal Aging Study Amsterdam, an ongoing cohort study in a representative sample of Dutch older persons. A total of 1286 subjects (629 men and 657 women) between the ages of 65 and 88 years participated in the study. Measurements Metabolic syndrome (U.S. National Cholesterol Education Program definition) and its individual components were assessed as well as serum 25 OHD levels. Results Among the participants, the prevalence of the metabolic syndrome was 37·0%. The mean 25 OHD level was 53·3 nm ; 47·8% had 25 OHD levels below 50 nm . There was a significantly increased risk of the metabolic syndrome in the subjects with serum 25 OHD levels below 50 nm , compared with that of subjects with levels over 50 nm [odds ratio (OR) = 1·54; 95% confidence interval (CI) 1·23–1·94]. After adjustment for confounders, age, sex, season, years of education, alcohol use, total activity, smoking and PTH, the OR was 1·29 (95% CI 1·00–1·68). The association between vitamin D deficiency and the metabolic syndrome was mainly determined by the components low HDL and (high) waist circumference. Conclusions Vitamin D deficiency is common in the older population in the Netherlands, and subjects with serum 25 OHD below 50 nm have a higher risk of the metabolic syndrome.     

Risk stratification of apolipoprotein B, apolipoprotein A1, and apolipoprotein B/AI ratio on the prevalence of the metabolic syndrome: the ATTICA study

We investigated the association of apolipoproteins AI and B in relation to the prevalence of metabolic syndrome in a random sample of cardiovascular disease- free adults from the ATTICA study (1,514 men, aged 18-87 y; 1,528 women, aged 18-89 y). Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The prevalence of metabolic syndrome was 25% in men and 15% in women (P < .001). Using the area under the Receiver Operation Characteristic curve, apolipoprotein B/AI was the best diagnostic marker of metabolic syndrome, the optimal discriminating cut-off value of this ratio was 0.72 (sensitivity 74%, specificity 67%), and individuals with apolipoprotein B/AI ratio greater than 0.74 had 3.29 times higher odds of having metabolic syndrome (95% confidence interval: 2.56-4.21) after adjusting for potential confounders.     

Association of the metabolic syndrome and insulin resistance with silent myocardial ischemia in patients with type 2 diabetes mellitus

Metabolic syndrome is associated with elevated morbidity and mortality for overt coronary artery disease (CAD). In diabetic patients, CAD is often silent. The relation between metabolic syndrome and silent CAD has never been studied. We investigated whether metabolic syndrome is associated with silent CAD in patients with type 2 diabetes mellitus. We evaluated the prevalence of metabolic syndrome in 169 patients with uncomplicated diabetes and angiographically verified silent CAD and in 158 diabetic patients without myocardial ischemia on exercise electrocardiography, 48-hours ambulatory electrocardiography, and stress echocardiography. The groups were comparable for gender, age, glycemic control, and diabetes duration. Metabolic syndrome was defined according to the National Cholesterol Education Program criteria. To estimate insulin resistance in patients treated with diet alone or oral agents (122 patients with CAD and 115 patients without CAD), the Homeostasis Model Insulin-Resistance Assessment (HOMA) was used. The prevalence of metabolic syndrome (59.8% vs 44.3%, p = 0.005) and HOMA (5.4 +/- 2.1 vs 4.9 +/- 2.8, p = 0.044) were significantly higher in those with CAD than in those without CAD. Multiple logistic regression analysis showed that the metabolic syndrome was associated with silent CAD (odds ratio 2.44, 95% confidence interval 1.19 to 5.02, p = 0.015). Among patients on diet alone or oral agents, the HOMA was the strongest predictor of silent CAD (odds ratio 10.16, 95% confidence interval 2.60 to 39.63, p < 0.001). In conclusion, our data have shown an independent association of metabolic syndrome and insulin resistance with silent CAD in patients with type 2 diabetes mellitus. Other studies are needed to establish whether metabolic syndrome and HOMA are reliable markers to identify diabetic patients for additional screening for silent CAD.     

Hemodynamics instability score in chronic fatigue syndrome and in non-chronic fatigue syndrome

OBJECTIVE: In studying patients with chronic fatigue syndrome (CFS) we developed a method that confers numerical expression to the degree of blood pressure and heart rate lability, ie, the 'hemodynamic instability score' (HIS). The HIS in CFS patients differed significantly from healthy subjects. The present investigation compares the HIS in CFS, non-CFS chronic fatigue and patients with recurrent syncope. METHODS: Patients with CFS (n = 21), non-CFS chronic fatigue (n = 24), syncope of unknown cause (n = 44), and their age and sex-matched healthy controls (n = 21) were evaluated with a standardized head-up tilt test (HUTT). Abnormal reactions (endpoints) on HUTT were classified 'clinical outcomes' (cardioinhibitory or vasodepressor reaction, orthostatic hypotension, postural tachycardia syndrome) and 'HIS endpoint', i.e. HIS >-0.98. RESULTS: The highest incidence of endpoints was noted in patients with CFS (79%), followed by patients with syncope of unknown cause (46%), non-CFS chronic fatigue (35%), and healthy subjects (14%). Presyncope or syncope during tilt occurred in 38% of CFS patients, 21% of patients with non-CFS chronic fatigue, and 43% of patients with recurrent syncope. The average HIS values were: CFS = +2.02 (SD 4.07), non-CFS chronic fatigue = -2.89 (SD 3.64), syncope = -3.2 (SD 3.0), healthy = -2.48 (4.07). The odds ratios for CFS patients to have HIS >-0.98 was 8.8 compared with non-CFS chronic fatigue patients, 14.6 compared with recurrent syncope patients, and 34.8 compared with healthy subjects. CONCLUSION: The cardiovascular reactivity in patients with CFS has certain features in common with the reactivity in patients with recurrent syncope or non-CFS chronic fatigue, such as the frequent occurrence of vasodepressor reaction, cardioinhibitory reaction, and postural tachycardia syndrome. Apart from to these shared responses, the large majority of CFS patients exhibit a particular abnormality which is characterized by HIS values >-0.98. Thus, HIS >-0.98 lends objective criteria to the assessment of CFS.     

Adolescent girls with polycystic ovary syndrome have an increased risk of the metabolic syndrome associated with increasing androgen levels independent of obesity and insulin resistance

CONTEXT: Adult women with polycystic ovary syndrome (PCOS) have an increased prevalence of the metabolic syndrome (MBS). The prevalence of MBS is also increasing in adolescents. OBJECTIVE: Our objective was to test the hypothesis that the prevalence of MBS is increased in adolescent girls with PCOS compared with the general population and to determine the factors associated with an increased risk of the MBS in PCOS. DESIGN AND SETTING: We conducted a cross-sectional case-control study at academic medical centers with general clinical research centers. PARTICIPANTS: Participants included 49 adolescent girls with PCOS and 165 girls from the Third National Health and Nutrition Examination Survey (NHANES III) adolescent population of similar age and ethnic background. MAIN OUTCOME MEASURE: We assessed the prevalence of MBS according to currently proposed adolescent MBS criteria. RESULTS: Thirty-seven percent of adolescent girls with PCOS had MBS compared with 5% of NHANES III girls (P < 0.0001). None of the girls of normal body mass index (BMI) had MBS, whereas 11% of overweight and 63% of obese girls with PCOS had MBS compared with 0 and 32% of NHANES III girls, respectively. Girls with PCOS were 4.5 times more likely to have MBS than age-matched NHANES III girls after adjusting for BMI (odds ratio, 4.5; 95% confidence interval, 1.1-17.7; P = 0.03). The odds of having the MBS were 3.8 times higher for every quartile increase in bioavailable testosterone in girls with PCOS after adjusting for BMI and insulin resistance (odds ratio, 3.8; 95% confidence interval, 1.4-10.2; P = 0.008). CONCLUSIONS: Adolescent girls with PCOS have a higher prevalence of MBS than the general adolescent population. Hyperandrogenemia is a risk factor for MBS independent of obesity and insulin resistance.     

The metabolic syndrome: prevalence and association to leisure-time and work-related physical activity in 60-year-old men and women

Background and aimThis study examined the prevalence of the metabolic syndrome and its association to lifestyle factors in 60-year-old men and women, with special emphasis on physical activity (PA).Methods and resultsEvery third 60-year-old man and woman in the Stockholm County, Sweden, was invited to a survey of cardiovascular risk factors. Seventy-seven percent of the sample, 4228 individuals, agreed to participate (2036 men and 2192 women). Participants underwent physical examination and laboratory tests, and completed a questionnaire. After excluding 364 subjects suffering from cardiovascular disease and/or cancer, the prevalence of the metabolic syndrome was 24% and 19% in men and women, respectively. The adjusted odds ratio for having the metabolic syndrome in the high leisure-time PA group was 0.33 (95% confidence interval: 0.22–0.51) using the low leisure-time PA group as reference. However, no such inverse association was noted for work-related PA.ConclusionsThis cross-sectional survey of 60-year-old men and women demonstrates a high prevalence of the metabolic syndrome. The robust inverse dose–response relationship between leisure-time PA and the metabolic syndrome emphasises the role of PA in the prevention and treatment of the metabolic syndrome.     

The metabolic syndrome,diabetes, and subclinical atherosclerosis assessed by coronary calcium

OBJECTIVES: We compared the prevalence and extent of coronary artery calcium (CAC) among persons with the metabolic syndrome (MetS), diabetes, and neither condition. BACKGROUND: The prevalence and extent of CAC has not been compared among those with MetS, diabetes, or neither condition. METHODS: Of 1,823 persons (36% female) age 20 to 79 years who had screening for CAC by computed tomography, 279 had MetS, 150 had diabetes, and the remainder (n = 1,394) had neither condition. Metabolic syndrome was defined with >or=3 of the following: body mass index >or=30 kg/m(2); high-density lipoprotein cholesterol <40 mg/dl if male or <50 mg/dl if female; triglycerides >or=150 mg/dl; blood pressure >or=130/85 mm Hg or on treatment; or fasting glucose 110 to 125 mg/dl. The prevalence and odds of any and significant (>or=75th percentile) CAC among these groups and by number of MetS risk factors were determined. RESULTS: Those with neither MetS nor diabetes, MetS, or diabetes had a prevalence of CAC of 53.5%, 58.8%, and 75.3% (p < 0.001), respectively, among men and 37.6%, 50.8%, and 52.6% (p < 0.001), respectively, among women. Coronary artery calcium increased by the number (0 to 5) of MetS risk factors (from 34.0% to 58.3%) (p < 0.001). Forty-one percent of subjects with MetS had either a >20% 10-year risk of CHD or CAC >or=75th percentile for age and gender. Risk factor-adjusted odds for the presence of CAC were 1.40 (95% confidence interval [CI] 1.05 to 1.87) among those with MetS and 1.67 (95% CI 1.12 to 2.50) among those with diabetes, versus those with neither condition. CONCLUSIONS: Those with MetS or diabetes have an increased likelihood of CAC compared with those having neither condition.     

Contribution of metabolic factors to alanine aminotransferase activity in persons with other causes of liver disease

BACKGROUND & AIMS: Nonalcoholic fatty liver disease has been defined by the presence of hepatic steatosis in the absence of other chronic liver diseases. We sought to determine whether obesity, insulin resistance, and the metabolic syndrome, which are the main risk factors for nonalcoholic fatty liver disease, are associated with similar elevations in serum alanine aminotransferase activity in persons with and those without other causes of chronic liver disease. METHODS: Adult participants of the third National Health and Nutrition Examination Survey were divided into those with causes of chronic liver disease (n = 1037), defined as viral hepatitis, excessive alcohol consumption, or increased transferrin-iron saturation, and those without (n = 8004). RESULTS: Among persons with other causes of chronic liver disease, obesity (adjusted odds ratio, 4.9; 95% confidence interval, 2.5-9.4), insulin resistance (adjusted odds ratio, 6.8; 95% confidence interval, 3.0-15.5, comparing the highest and the lowest quartile), and the metabolic syndrome (adjusted odds ratio, 3.3; 95% confidence interval, 1.4-8.0) were all strongly associated with increased alanine aminotransferase activity (>43 IU/L). Among persons without other causes of chronic liver disease, statistically similar associations were identified. CONCLUSIONS: Obesity, insulin resistance, and the metabolic syndrome are strong predictors of increased alanine aminotransferase activity in the US population, both in persons with and in persons without other causes of chronic livers disease. We hypothesize that metabolic fatty liver disease related to these conditions is the cause of the increased alanine aminotransferase activity and may be underrecognized in persons with other causes of chronic liver disease.     

Results of isoproterenol tilt table testing in monozygotic twins discordant for chronic fatigue syndrome

BACKGROUND: The pathogenesis of chronic fatigue syndrome (CFS) is unknown. Neurally mediated hypotension (NMH) has been suggested as a common comorbid condition or a potential underlying cause. METHODS: We conducted a cotwin control study of 21 monozygotic twins who were discordant for CFS. One twin met the 1994 Centers for Disease Control and Prevention criteria for CFS, and the other twin was healthy and denied chronic fatigue. The twins were selected from a volunteer twin registry in which at least 1 member reported persistent fatigue. As part of a 7-day clinical evaluation, all 21 twin pairs were evaluated with a 3-stage tilt table test with isoproterenol hydrochloride for the assessment of NMH. The presence of NMH was defined as syncope or presyncope associated with a decrease of 25 mm Hg in blood pressure and no associated increase in heart rate. RESULTS: A positive tilt table test result was observed in 4 twins with CFS (19%) and in 4 healthy twins (19%). This difference was not statistically significant (matched pair odds ratio, 1.0; 95% confidence interval, 0.2-5.4; P>.90). Compared with the healthy twins, the twins with CFS reported more severe symptoms of CFS and NMH both in the week before and during the tilt table test. CONCLUSIONS: These results do not support a major role for NMH in CFS. They highlight the importance of selecting well-matched control subjects, as well as the unique value of the monozygotic cotwin control design in the study of this illness. Arch Intern Med. 2000;160:3461-3468.     

Lack of association between cassava consumption and tropical pancreatitis syndrome

Previous studies suggesting an association between use of tubers of cassava and tropical pancreatitis have been weak and conflicting. To test a possible association the cassava consumption of 40 consecutive cases of tropical pancreatitis syndrome were compared with age-matched and sex-matched healthy hospital visitors. The sociodemographic characteristics of the two groups were comparable. There was no association between cassava consumption and tropical pancreatitis syndrome (odds ratio = 0.56; 95% confidence interval = 0.21–1.45). Controlling for the possible confounding effects of low socio-economic status and vegetarian diet did not alter the odds ratio. Testing for interaction also failed to show any effect modification of the association of cassava by economic status, chilli consumption or vegetarian diet. A significantly higher number of cases gave a positive family history of diabetes compared to the controls (odds ratio = 4.11; 95% confidence interval = 1.04–16.30; P= 0.04). In this case-control study which had sufficient power to detect an odds ratio ? 3.5, there was no association between cassava consumption and tropical pancreatitis syndrome.     

Thyroid function and prevalent and incident metabolic syndrome in older adults: the Health, Ageing and Body Composition Study

Objective Both subclinical hypothyroidism and the metabolic syndrome have been associated with increased risk of coronary heart disease events. It is unknown whether the prevalence and incidence of metabolic syndrome is higher as TSH levels increase, or in individuals with subclinical hypothyroidism. We sought to determine the association between thyroid function and the prevalence and incidence of the metabolic syndrome in a cohort of older adults. Design Data were analysed from the Health, Ageing and Body Composition Study, a prospective cohort of 3075 community‐dwelling US adults. Participants Two thousand one hundred and nineteen participants with measured TSH and data on metabolic syndrome components were included in the analysis. Measurements TSH was measured by immunoassay. Metabolic syndrome was defined per revised ATP III criteria. Results At baseline, 684 participants met criteria for metabolic syndrome. At 6‐year follow‐up, incident metabolic syndrome developed in 239 individuals. In fully adjusted models, each unit increase in TSH was associated with a 3% increase in the odds of prevalent metabolic syndrome (OR, 1·03; 95% CI, 1·01–1·06; P = 0·02), and the association was stronger for TSH within the normal range (OR, 1·16; 95% CI, 1·03–1·30; P = 0·02). Subclinical hypothyroidism with a TSH > 10 mIU/l was significantly associated with increased odds of prevalent metabolic syndrome (OR, 2·3; 95% CI, 1·0–5·0; P = 0·04); the odds of incident MetS was similar (OR 2·2), but the confidence interval was wide (0·6–7·5). Conclusions Higher TSH levels and subclinical hypothyroidism with a TSH > 10 mIU/l are associated with increased odds of prevalent but not incident metabolic syndrome.