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Biomedical subjects

Jeanne M Clark

Publications and source records attributed to Jeanne M Clark.

At least 19 recordsLinked to original sources

Lifetime weight patterns in male physicians: the effects of cohort and selective survival.

OBJECTIVE: The natural history of lifetime weight change is not well understood because of conflicting evidence from cross-sectional and longitudinal studies. Cross-sectional analyses find that adult weight is highest at approximately 60 years of age and lower thereafter. Longitudinal analyses have not found this pattern. Our objective was to test whether cohort effects and selective survival may explain the differences observed between cross-sectional and longitudinal studies. RESEARCH METHODS AND PROCEDURES: We analyzed data on white men from the Johns Hopkins Precursors Study (n = 1197). Weight and height were measured at enrollment during medical school. The Precursors Study collected subsequent weight measurements by self-report and follows all participants for mortality. RESULTS: In preliminary analyses that ignored cohort and survival effects, average weight increased 0.16 kg/yr to age 65 (p < 0.001) and declined 0.10 kg/yr thereafter (p = 0.002). When controlling for differing rates of weight change by cohort and survival group, the apparent decline after 65 years of age was mostly explained. DISCUSSION: These data suggest that, in white men, weight increases steadily until age 65 and then plateaus. These findings emphasize the necessity of longitudinal rather than cross-sectional data to describe lifetime weight patterns.

Age Factors↗

A national collaboration to disseminate skills for outpatient teaching in internal medicine: program description and preliminary evaluation.

The shift of clinical care and teaching to outpatient settings has challenged ambulatory and community-based teachers. To address this challenge, U.S. internal medicine organizations devised "Faculty Development for General Internal Medicine: Generalist Faculty Teaching in Ambulatory Settings," a national program to train leaders to create local faculty development projects. In 1999, teams from all 386 internal medicine training institutions were invited to apply. Participation required an acceptable plan for a local project and inclusion of an institutional leader, residency or clerkship director, and a community-based faculty member on the project team. Team members attended one of three national training conferences held in 1999 and 2000 that included plenary sessions, workshops, and team meetings. Participants were invited to a wrap-up conference to present their accomplishments. One hundred ten teams from 57 university and 53 non-university hospitals attended the training conferences; 412 (93%) participants returned conference evaluations. All sessions were rated highly. Participants preferred workshops and team meetings to plenary sessions. Two hundred thirty-five (57%) would have recommended the training conference to colleagues as an outstanding experience; 148 (36%) as a good experience; and 25 (6%) as a satisfactory experience. Forty-nine teams (122 participants) returned for the wrap up conference where 35 teams presented their local faculty development projects. Cost per team trained was US$11,818. This program demonstrated a national desire for training in teaching skills, reached a broad audience of ambulatory-based clinical teachers, provided highly rated faculty development conferences in teaching skills, and facilitated development of a variety of local projects at modest expense. Partnerships were forged between academic leaders and community-based teachers.

Ambulatory Care↗

The epidemiology of nonalcoholic fatty liver disease in adults.

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that has been shown to progress to cirrhosis and hepatocellular carcinoma. This article reviews the prevalence of NAFLD and the factors associated this disorder, and with the more advanced stages of NAFLD, including nonalcoholic steatohepatitis (NASH) and fibrosis. In the general population, the estimated prevalence ranges from 3% to 24%, with most estimates in the 6% to 14% range. NAFLD is extremely common among patients undergoing bariatric surgery, ranging from 84% to 96%. In these patients, 25% to 55% have NASH, 34% to 47% have fibrosis, and 2% to 12% have bridging fibrosis or cirrhosis. NAFLD appears to be most strongly associated with obesity, and insulin resistance states including diabetes and with other features of the metabolic syndrome, such as high triglycerides and low HDL. It appears to be more common in men, and it increases with increasing age and after menopause. Some data suggest that Mexican Americans are more likely to have NAFLD and blacks are less likely compared with non-Hispanic whites. More advanced stages of NAFLD are associated with older age, higher body mass index, diabetes, hypertension, high triglycerides, and/or insulin resistance. An AST/ALT ratio greater >1 may also indicate more severe disease. Although hepatocellular carcinoma can occur in the setting of NAFLD, the risk factors for hepatocellular carcinoma in the setting of NAFLD have not been established. More prospective studies are needed to determine the true risk factors for the development and progression of NAFLD to help identify patients at highest risk who might benefit from treatment trials.

Carcinoma, Hepatocellular↗

Weight loss as a treatment for nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that can progress to cirrhosis and hepatocellular carcinoma. NAFLD has been associated with obesity and other features of the metabolic syndrome, including insulin resistance, impaired glucose tolerance, and dyslipidemia. As a result, and with a lack of other effective treatments, weight loss achieved through lifestyle modifications (diet and exercise) has been promoted as the standard treatment. However, there is very little empiric evidence to support the effectiveness of weight loss for NAFLD. This article reviews the current literature on the effects of weight loss achieved through lifestyle modification or medications on NAFLD. To date, there have been no randomized controlled trials of weight loss interventions on hepatic pathology. Only three published trials (N = 89 subjects), which include a comparison group, have been published. These studies suggest improvement in liver enzymes and/or hepatic pathology; however, direct between group comparisons are lacking. Four small, nonrandomized studies (N = 59 subjects) have evaluated the effect of weight loss achieved with medications (4 of orlistat, 1 of sibutramine) on NAFLD. These suggest some improvement in liver enzymes and histopathology. Finally, a brief review of observational studies on the association between NAFLD pathology or liver enzymes and diet composition suggests a possible role for the manipulation of macronutrients and/or micronutrients in NAFLD treatment. In summary, there is little empiric evidence to support the role of weight loss achieved through lifestyle modification or medication in the treatment of NAFLD. Rigorously conducted, randomized controlled trials are needed in this area.

Anti-Obesity Agents↗

Arsenic exposure and type 2 diabetes: a systematic review of the experimental and epidemiological evidence.

Chronic arsenic exposure has been suggested to contribute to diabetes development. We performed a systematic review of the experimental and epidemiologic evidence on the association of arsenic and type 2 diabetes. We identified 19 in vitro studies of arsenic and glucose metabolism. Five studies reported that arsenic interfered with transcription factors involved in insulin-related gene expression: upstream factor 1 in pancreatic beta-cells and peroxisome proliferative-activated receptor gamma in preadipocytes. Other in vitro studies assessed the effect of arsenic on glucose uptake, typically using very high concentrations of arsenite or arsenate. These studies provide limited insight on potential mechanisms. We identified 10 in vivo studies in animals. These studies showed inconsistent effects of arsenic on glucose metabolism. Finally, we identified 19 epidemiologic studies (6 in high-arsenic areas in Taiwan and Bangladesh, 9 in occupational populations, and 4 in other populations). In studies from Taiwan and Bangladesh, the pooled relative risk estimate for diabetes comparing extreme arsenic exposure categories was 2.52 (95% confidence interval, 1.69-3.75), although methodologic problems limit the interpretation of the association. The evidence from occupational studies and from general populations other than Taiwan or Bangladesh was inconsistent. In summary, the current available evidence is inadequate to establish a causal role of arsenic in diabetes. Because arsenic exposure is widespread and diabetes prevalence is reaching epidemic proportions, experimental studies using arsenic concentrations relevant to human exposure and prospective epidemiologic studies measuring arsenic biomarkers and appropriately assessing diabetes should be a research priority.

Air Pollutants↗

Roux-en-Y gastric bypass improves liver histology in patients with non-alcoholic fatty liver disease.

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the United States and is prevalent in morbidly obese patients. While weight loss and treatment of risk factors are recommended, the reported effects of bariatric surgery on NAFLD are mixed. RESEARCH METHODS AND PROCEDURES: We examined liver histology at the time of Roux-en-Y gastric bypass surgery and at elective incisional hernia repair after weight loss for 16 patients at one center. Slides were read by one pathologist, blinded to clinical data, using the Brunt criteria. Clinical and laboratory data were extracted from chart review. Alcohol use was ascertained by two interviews. RESULTS: At baseline, the mean age was 44 years, 50% were women, 88% were white, and the mean BMI was 51 kg/m2. None had significant alcohol use. On initial biopsy, all patients showed steatosis, 94% had inflammation, 88% had ballooning degeneration, 88% had perisinusoidal fibrosis, and 81% had portal fibrosis. The mean time between the two biopsies was 305 +/- 131 (SD) days. The mean weight loss was 118 +/- 29 lb. Steatosis improved in 15 of 16 patients, with resolution in 13. Twelve of 15 patients with inflammation at baseline showed improvement, and 12 of 14 showed less ballooning. Six of 14 patients with perisinusoidal fibrosis and 6 of 13 with portal fibrosis showed improvement. No patient had worsening of steatosis, inflammation, ballooning, or fibrosis. DISCUSSION: Our study shows improvement in all of the histological features of NAFLD after Roux-en-Y gastric bypass surgery-induced weight loss, despite significant histopathology at baseline and substantial weight loss.

Adult↗

Hepatic 31P magnetic resonance spectroscopy: a hepatologist's user guide.

Hepatic phosphorus magnetic resonance spectroscopy (31P MRS) offers the exciting potential of studying metabolic processes in the human liver in vivo. Many investigators have utilized 31P MRS to research a broad range of metabolic questions, and there is outstanding potential for this imaging modality in the future. However, at times it is difficult to appreciate this potential because most published series have been small, and comparisons between studies are difficult. Indeed, the published literature contains significant variation in data acquisition and data analysis techniques and, perhaps most importantly, the interpretation of the data itself. As MR technology continues to evolve and more studies are being performed, perhaps a greater consensus of study techniques and endpoints will emerge. This review summarizes the present literature on human hepatic 31P MRS.

Gastroenterology↗

Racial and socioeconomic differences in the weight-loss experiences of obese women.

Focus groups stratified by race and socioeconomic status were used to examine obese women's experiences with weight-loss methods. Six themes emerged: failure of weight maintenance, use of psychological and spiritual approaches, role of family influences and societal expectations, role of African American subculture, method affordability, and racial differences in weight-loss methods. Tailored weight-management interventions for women, particularly African Americans and those of low socioeconomic status, should account for features of African American subculture and address affordability concerns, include maintenance strategies that incorporate psychological and spiritual principles, and target family attitudes and behaviors.

Adult↗

Dietary composition and nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a common and potentially serious form of chronic liver disease that occurs in patients who do not abuse alcohol. Present dietary recommendations for all Americans, including those with NAFLD, endorse a low-calorie, low-fat diet. However, little is known about the effect of diet composition on liver histopathology in patients with NAFLD. The aim of this study was to determine whether overall calorie intake and diet composition are associated with the severity of NAFLD histopathology. Seventy-four consecutive morbidly obese patients presenting for bariatric surgery from January 2001 to March 2002 were retrospectively reviewed. In addition to a standard surgical and psychological evaluation, all patients underwent a preoperative dietary evaluation using a standardized 24-hr food recall. Food intake was evaluated for total calories and macronutrients and compared to liver histopathology from biopsies routinely obtained during surgery. Associations with the severity of steatosis and the presence of inflammation or fibrosis were assessed separately using chi-square for categorical variables and ANOVA for continuous variables. Further, we conducted multiple logistic regression analyses for each histological outcome. There were no significant associations between either total caloric intake or protein intake and either steatosis, fibrosis, or inflammation. However, higher CHO intake was associated with significantly higher odds of inflammation, while higher fat intake was associated with significantly lower odds of inflammation. In conclusion, present dietary recommendations may worsen NAFLD histopathology.

Adult↗

Teaching the teachers: national survey of faculty development in departments of medicine of U.S. teaching hospitals.

OBJECTIVE: To determine the prevalence, topics, methods, and intensity of ongoing faculty development (FD) in teaching skills. DESIGN: Mailed survey. PARTICIPANTS: Two hundred and seventy-seven of the 386 (72%) U.S. teaching hospitals with internal medicine residency programs. MEASUREMENTS: Prevalence and characteristics of ongoing FD. RESULTS: One hundred and eight teaching hospitals (39%) reported ongoing FD. Hospitals with a primary medical school affiliation (university hospitals) were more likely to have ongoing FD than non-university hospitals. For non-university hospitals, funding from the Health Resources Services Administration and >50 house staff were associated with ongoing FD. For university hospitals, >100 department of medicine faculty was associated. Ongoing programs included a mean of 10.4 topics (standard deviation, 5.4). Most offered half-day workshops (80%), but 22% offered > or =1-month programs. Evaluations were predominantly limited to postcourse evaluations forms. Only 14% of the hospitals with ongoing FD (5% of all hospitals) had "advanced" programs, defined as offering > or =10 topics, lasting >2 days, and using > or =3 experiential teaching methods. These were significantly more likely to be university hospitals and to offer salary support and/or protected time to their FD instructors. Generalists and hospital-based faculty were more likely to receive training than subspecialist and community-based faculty. Factors facilitating participation in FD activities were supervisor attitudes, FD expertise, and institutional culture. CONCLUSIONS: A minority of U.S. teaching hospitals offer ongoing faculty development in teaching skills. Continued progress will likely require increased institutional commitment, improved evaluations, and adequate resources, particularly FD instructors and funding.

Data Collection↗

Faculty development needs.

We compared prior training in 4 areas (general teaching skills, teaching specific content areas, teaching by specific methods and in specific settings, and general professional skills) among community-based teachers based in private practices (N = 61) compared with those in community sites operated by teaching institutions (N = 64) and hospital-based faculty (N = 291), all of whom attended one of three national faculty development conferences. The prevalence of prior training was low. Hospital-based faculty reported the most prior training in all 4 categories, teaching hospital affiliated community-based teachers an intermediate amount, and private practice community-based teachers the least (all P <.05). This association remained after multivariable adjustment for age, gender, and amount of time spent in teaching and clinical activities. Preferences for future training reported frequently by the private practice community-based teachers included: time management (48%); teaching evidence-based medicine (46%); evaluation of learners (38%); giving feedback (39%); outpatient precepting (38%); and "teaching in the presence of the patient" (39%).

Adult↗

Outcomes of a national faculty development program in teaching skills: prospective follow-up of 110 medicine faculty development teams.

BACKGROUND: Awareness of the need for ambulatory care teaching skills training for clinician-educators is increasing. A recent Health Resources and Services Administration (HRSA)-funded national initiative trained 110 teams from U.S. teaching hospitals to implement local faculty development (FD) in teaching skills. OBJECTIVE: To assess the rate of successful implementation of local FD initiatives by these teams. METHODS: A prospective observational study followed the 110 teams for up to 24 months. Self-reported implementation, our outcome, was defined as the time from the training conference until the team reported that implementation of their FD project was completely accomplished. Factors associated with success were assessed using Kaplan-Meier analysis. RESULTS: The median follow-up was 18 months. Fifty-nine of the teams (54%) implemented their local FD project and subsequently trained over 1,400 faculty, of whom over 500 were community based. Teams that implemented their FD projects were more likely than those that did not to have the following attributes: met more frequently (P=.001), had less turnover (P=.01), had protected time (P=.01), rated their likelihood of success high (P=.03), had some project or institutional funding for FD (P=.03), and came from institutions with more than 75 department of medicine faculty (P=.03). The cost to the HRSA was $22,033 per successful team and $533 per faculty member trained. CONCLUSIONS: This national initiative was able to disseminate teaching skills training to large numbers of faculty at modest cost. Smaller teaching hospitals may have limited success without additional support or targeted funding.

Education, Medical, Continuing↗

Serum ferritin and risk of the metabolic syndrome in U.S. adults.

OBJECTIVE: We examined the relationship among iron stores, the metabolic syndrome, and insulin resistance. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional study of 6,044 adults >20 years of age who participated in the Third National Health and Nutrition Examination Survey. Metabolic syndrome was defined as the presence of at least three of the following: elevated blood pressure, low HDL cholesterol, elevated serum triglycerides, elevated plasma glucose, and abdominal obesity. Insulin resistance was estimated using homeostasis model assessment (for insulin resistance), fasting insulin, and triglyceride-to-HDL cholesterol ratio. RESULTS: After excluding individuals with likely hemochromatosis, mean serum ferritin values in premenopausal women, postmenopausal women, and men were 33.6, 93.4, and 139.9 microg/l, respectively. Metabolic syndrome was more common in those with the highest compared with the lowest levels of serum ferritin in premenopausal women (14.9 vs. 6.4%, P = 0.002), postmenopausal women (47.5 vs. 28.2%, P < 0.001), and men (27.3 vs. 13.8%, P < 0.001). Insulin resistance also increased across quartiles of serum ferritin for men and postmenopausal women and persisted after adjustment for age, race/ethnicity, C-reactive protein, smoking, alcohol intake, and BMI. CONCLUSIONS: Elevated iron stores were positively associated with the prevalence of the metabolic syndrome and with insulin resistance.

Adult↗

Nonalcoholic fatty liver disease: an underrecognized cause of cryptogenic cirrhosis.

Cryptogenic cirrhosis is a common cause of liver-related morbidity and mortality in the United States. Nonalcoholic fatty liver disease (NAFLD) is now recognized as the most common cause of cryptogenic cirrhosis. However, the diagnosis of cirrhosis in patients with NAFLD appears to be delayed compared with those with other chronic liver diseases and thus carries a higher mortality rate. This delay in diagnosis is illustrated in our case of a 53-year-old man who presented with hepatic hydrothorax and ascites, whose workup revealed cirrhosis due to NAFLD. Although a diagnosis of presumed NAFLD can be made noninvasively, a definitive diagnosis requires a liver biopsy specimen. A biopsy specimen is also important for detecting histologically advanced disease, which may be clinically silent and undetected by aminotransferases or diagnostic imaging. Although there are no proven treatments, recommendations for patients with NAFLD include avoidance of hepatotoxins and aggressive management of associated conditions, such as hypertriglyceridemia and type 2 diabetes mellitus.

Ascites↗

Prevalence and correlates of obesity in a community sample of individuals with severe and persistent mental illness.

Individuals with severe and persistent mental illness (SPMI) have a preponderance of weight problems, possibly even greater than the obesity epidemic in the general population. Although atypical antipsychotics cause weight gain, their contribution to obesity has not been characterized in a community setting where individuals may take multiple psychotropics associated with weight gain. Using survey information including measured height and weight from a random sample of Maryland Medicaid recipients with SPMI, we compared obesity prevalence to the National Health and Nutrition Examination Survey (NHANES III) sample and a Maryland sample (Behavioral Risk Factor Surveillance System) of the general population adjusted to SPMI demographic characteristics. We investigated correlates of obesity in the SPMI sample. The results indicate that both men and especially women with SPMI had a higher prevalence of obesity than the general population; this portends substantial health implications. A fourfold association between atypical antipsychotics and prevalent obesity was found in men but not in women; further work should clarify mechanisms of obesity in the SPMI.

Adult↗

The prevalence and etiology of elevated aminotransferase levels in the United States.

Chronic liver disease is a major cause of morbidity and mortality in the United States. Although often used to detect liver disease, the prevalence and etiology of elevated aminotransferases are unknown. We analyzed data on adults ages 17 yr and older (N = 15,676) from the Third National Health and Nutrition Examination Survey (1988-1994). Participants were classified as having elevated aminotransferase levels if either aspartate aminotransferase or alanine aminotransferase was elevated above normal. Aminotransferase elevation was classified as "explained" if there was laboratory evidence of hepatitis B or C infection, iron overload, or if there was a history of alcohol consumption. Analyses were weighted to provide national estimates. The prevalence of aminotransferase elevation in the United States was 7.9%. Aminotransferase elevation was more common in men compared to women (9.3% vs 6.6%, p = 0.002), in Mexican Americans (14.9%) and non-Hispanic blacks (8.1%) compared to non-Hispanic whites (7.1%, p < 0.001). High alcohol consumption, hepatitis B or C infection and high transferrin saturation were found in only 31.0% of cases. Aminotransferase elevation was unexplained in the majority (69.0%). In both men and women, unexplained aminotransferase elevation was significantly associated with higher body mass index, waist circumference, triglycerides, fasting insulin, and lower HDL; and with type 2 diabetes and hypertension in women (all p < 0.05). Aminotransferase elevation was common in the United States, and the majority could not be unexplained by alcohol consumption, viral hepatitis or hemochromatosis. Unexplained aminotransferase elevation was strongly associated with adiposity and other features of the metabolic syndrome, and thus may represent nonalcoholic fatty liver disease.

Adult↗