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Biomedical subjects

K M Narayan

Publications and source records attributed to K M Narayan.

At least 19 recordsLinked to original sources
PubMed2003

Prevention of type 2 diabetes: data from recent trials.

All four main studies of lifestyle intervention on diabetes incidence found a clear benefit for diet and exercise intervention compared with usual care. Although the study populations differed by race and ethnicity, the mean BMI, and the intensity of the lifestyle intervention provided, all investigators found substantial diabetes risk reduction with modest weight loss and increased physical activity. Results of these trials give health care providers useful and heartening information to share with patients at risk for diabetes. The challenge remains to find feasible and cost-efficient methods to identify people at risk and to deliver effective lifestyle interventions. Findings from trials of pharmacologic agents such as metformin, acarbose, and troglitazone are encouraging; however, the ADA recommends that drug therapy should not be used routinely to prevent diabetes until more information regarding the cost-effectiveness of such intervention is known [20]. Results from trials that found a lower incidence of diabetes among those randomly assigned to angiotensin-converting enzyme inhibitors, statins, or hormone therapy are intriguing but must be viewed with caution because they are based on post hoc analyses. Because it is difficult to conduct randomized controlled trials of major operative procedures such as bariatric surgery, observational studies that compare surgical interventions for weight loss with traditional weight-loss management may be the best evidence available. These studies have the potential for healthy-person bias in that people who choose bariatric surgery may have other healthy behaviors that are often difficult to measure and control for; such behaviors could account for their lower incidence of diabetes. Undeniably, the best test to diagnose those at high risk for diabetes is not yet known. New strategies that identify those with pre-diabetes and that overcome the limitations of the current tests, particularly the 2-hour post-challenge glucose test, are needed.

Diabetes Mellitus, Type 2↗
PubMed2001

Fingerprint ridge-count difference between adjacent fingertips (dR45) predicts upper-body tissue distribution: evidence for early gestational programming.

Fingerprint ridge counts, which remain constant from the 19th week of pregnancy, are related to fingertip growth during early gestation. Each finger corresponds neurologically to a spinal-cord segment ranging from C6 (thumb, relatively cephalad) to C8 (fifth finger, relatively caudad). The authors hypothesized that large ridge-count differences between fingertips (cephalad > caudad) might reflect fetal inhibition of caudal growth. Among 69 male Atlanta, Georgia, military recruits (1994-1997; aged 17-22 years), they tested associations of the anthropometric waist-to-thigh ratio with 20 ridge-count differences. Waist-to-thigh ratio was associated with the ridge-count difference between the right fourth and fifth fingertips only (dR45; r = 0.36, p = 0.003). The race-adjusted standardized regression coefficient was 0.22 (95% confidence interval: 0.03, 0.41). Since upper-body tissue distribution indicates disease risk, the authors then tested the association of age (an indicator of survivorship) with dR45 in a sample of 135 male patients from Bangalore, India (1989-1990; aged 38-82 years). Age was inversely associated with dR45 (r = -0.17, p = 0.04), notably among the 75 men with diabetes (r = -0.22, p = 0.06). An increased dR45 predicts an upper-body tissue distribution originating before the midpoint of pregnancy. The cause of this developmental pattern is unknown, but it may lead to reduced survivorship.

Adolescent↗
PubMed2001

Prevalence of type 2 diabetes mellitus in Taiwan: ethnic variation and risk factors.

The purpose of this study was to compare the prevalence of diabetes and risk factors for the disease in three ethnic groups in Taiwan; the Hakaas, Fukienese, and aborigines. A cross-sectional study of men and women aged 50-79 years were invited to attend a standardized interview and physical examination. Diabetes mellitus was defined as a fasting plasma glucose (concentration of greater than or = 126) or a previous diagnosis of diabetes. Demographic, socioeconomic, and risk factor data were obtained. A total of 1293 persons (468 Hakaas, 440 Fukienese, and 385 aborigines) completed the examination. Hakaas had the highest age-adjusted prevalence of diabetes, 17.9% in men and 15.5% in women, followed by Fukienese, 14.5% in men and 12.8% in women. Aborigines had a prevalence of 10.0% in men and 13.3% in women. Diabetes prevalence was positively associated with family history of diabetes, obesity, hypertension, and hypertriglyceridemia. The ethnic variation in diabetes prevalence was reduced after adjustment for age, sex and significant factors. The multivariate-adjusted odds ratios (95% confidence interval) were 1.27 (0.76-2.12) for Fukienese and 1.44 (0.89-2.33) for Hakaas compared with aborigines. Diabetes mellitus is a major public health problem in Taiwan and warrants prevention efforts tailored to the country's different ethnic groups.

Age Factors↗
PubMed2001

Use of diabetes preventive care and complications risk in two African-American communities.

BACKGROUND: We examined levels of diabetes preventive care services and glycemic and lipid control among African Americans with diabetes in two North Carolina communities. METHODS: Cross-sectional, population-based study of 625 African-American adults with diagnosed diabetes. Participants had a household interview to determine receipt of preventive care services including glycosylated hemoglobin (HbA(1c)), blood pressure, lipid, foot, dilated eye, and dental examinations; diabetes education; and health promotion counseling. A total of 383 gave blood samples to determine HbA(1c) and lipid values. RESULTS: Annual dilated eye, foot, and lipid examinations were reported by 70% to 80% of the population, but only 46% reported HbA(1c) tests. Rates of regular physical activity (31%) and daily self-monitoring of blood glucose (40%) were low. Sixty percent of the population had an HbA(1c) level >8% and one fourth had an HbA(1c) level >10%. Half of the population had a low-density lipoprotein value >130 mg/dL. Lack of insurance was the most consistent correlate of inadequate care (odds ratio [OR]=2.3; 95% confidence interval [CI]=1.3-3.9), having HbA(1c) >9.5% (OR=2.1, 95% CI=1.1-4.2), and LDL levels >130 mg/dL (OR=2.1; 95% CI=1.0-4.5). CONCLUSIONS: Levels of diabetes preventive care services were comparable to U.S. estimates, but glycemic and lipid control and levels of self-management behaviors were poor. These findings indicate a need to understand barriers to achieving and implementing good glycemic and lipid control among African Americans with diabetes.

Adolescent↗
PubMed2001

Tobacco, betel quid, alcohol, and illicit drug use among 13- to 35-year-olds in I-Lan, rural Taiwan: prevalence and risk factors.

OBJECTIVES: This study determined the prevalence of and risk factors for substance use among rural Taiwanese. METHODS: We used a survey of a representative sample of 6318 participants aged 13 to 35 years in I-Lan, Taiwan, in 1996 through 1997. RESULTS: Perceived use of illicit drugs by peers, tobacco smoking, betel quid chewing, and male gender were the strongest predictors of illicit drug use. The prevalence of illicit drug use ranged from 0.3% among those who did not use any other substance to 7.1% among those using tobacco, betel quid, and alcohol. CONCLUSIONS: Preventive measures should address substance use in general rather than aiming at single substances.

Adolescent↗
PubMed2001

Performance of recommended screening tests for undiagnosed diabetes and dysglycemia.

OBJECTIVE: To evaluate the performance, in settings typical of opportunistic and community screening programs, of screening tests currently recommended by the American Diabetes Association (ADA) for detecting undiagnosed diabetes. RESEARCH DESIGN AND METHODS: Volunteers aged > or =20 years without previously diagnosed diabetes (n = 1,471) completed a brief questionnaire and underwent recording of postprandial time and measurement of capillary blood glucose (CBG) with a portable sensor. Participants subsequently underwent a 75-g oral glucose tolerance test; fasting serum glucose (FSG) and 2-h postload serum glucose (2-h SG) concentrations were measured. The screening tests we studied included the ADA risk assessment questionnaire, the recommended CBG cut point of 140 mg/dl, and an alternative CBG cut point of 120 mg/dl. Each screening test was evaluated against several diagnostic criteria for diabetes (FSG > or =126 mg/dl, 2-h SG > or =200 mg/dl, or either) and dysglycemia (FSG > or =110 mg/dl, 2-h SG > or =140 mg/dl, or either). RESULTS: Among all participants, 10.7% had undiagnosed diabetes (FSG > or =126 or 2-h SG > or =200 mg/dl), 52.1% had a positive result on the questionnaire, 9.5% had CBG > or =140 mg/dl, and 18.4% had CBG > or =120 mg/dl. The questionnaire was 72-78% sensitive and 50-51% specific for the three diabetes diagnostic criteria; CBG > or =140 mg/dl was 56-65% sensitive and 95-96% specific, and CBG > or =120 mg/dl was 75-84% sensitive and 86-90% specific. CBG > or =120 mg/dl was 44-62% sensitive and 89-90% specific for dysglycemia. CONCLUSIONS: Low specificity may limit the usefulness of the ADA questionnaire. Lowering the cut point for a casual CBG test (e.g., to 120 mg/dl) may improve sensitivity and still provide adequate specificity.

Adult↗
PubMed2001

Projection of diabetes burden through 2050: impact of changing demography and disease prevalence in the U.S.

OBJECTIVE: To project the number of people with diagnosed diabetes in the U.S. through 2050, accounting for changing demography and diabetes prevalence rates. RESEARCH DESIGN AND METHODS: We combined age-, sex-, and race-specific diagnosed diabetes prevalence rates-predicted from 1980-1998 trends in prevalence data from the National Health Interview Survey-with Bureau of Census population demographic projections. Sensitivity analyses were performed by varying both prevalence rate and population projections. RESULTS: The number of Americans with diagnosed diabetes is projected to increase 165%, from 11 million in 2000 (prevalence of 4.0%) to 29 million in 2050 (prevalence of 7.2%). The largest percent increase in diagnosed diabetes will be among those aged > or =75 years (+271% in women and +437% in men). The fastest growing ethnic group with diagnosed diabetes is expected to be black males (+363% from 2000-2050), with black females (+217%), white males (+148%), and white females (+107%) following. Of the projected 18 million increase in the number of cases of diabetes in 2050, 37% are due to changes in demographic composition, 27% are due to population growth, and 36% are due to increasing prevalence rates. CONCLUSIONS: If recent trends in diabetes prevalence rates continue linearly over the next 50 years, future changes in the size and demographic characteristics of the U.S. population will lead to dramatic increases in the number of Americans with diagnosed diabetes.

Adolescent↗
PubMed2001

Aspirin use among adults with diabetes: estimates from the Third National Health and Nutrition Examination Survey.

OBJECTIVE: Since 1997, the American Diabetes Association has recommended that aspirin therapy be considered for adults with diabetes who have cardiovascular disease (CVD) or CVD risk factors. We examined the prevalence of regular aspirin use among adults in the U.S. with diagnosed diabetes. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey (1988-1994) used a probability sample of the U.S. population and included an interview, physical examination, and laboratory studies. Among the survey participants were 1,503 adults (age > or =21 years) with self-reported diabetes. We defined regular aspirin use as reported having taken aspirin > or = 15 times in the previous month. CVD conditions were self-reported heart attack and stroke and symptoms of angina and claudication. CVD risk factors included smoking, hypertension, obesity, albuminuria, lipid abnormalities, and family history of heart attack. RESULTS: An estimated 27% of adults with diabetes had CVD, and an additional 71% had one or more CVD risk factors. Aspirin was used regularly by 37% of those with CVD and by 13% of those with risk factors only Adjusted odds of regular aspirin use were significantly greater for individuals with CVD than for those with one CVD risk factor (odds ratio [OR] = 4.3); for non-Hispanic whites than for blacks, Mexican-Americans, and others (OR = 2.5); and for individuals age 40-59 years than for those <40 years (OR = 33.3). CONCLUSIONS: Nearly every adult in the U.S. with diabetes has at least one risk factor for CVD and thus may be considered a potential candidate for aspirin therapy. During 1988-1994, only 20% (95% CI 16-23) took aspirin regularly Major efforts are needed to increase aspirin use.

Adult↗
PubMed2001

Effectiveness of self-management training in type 2 diabetes: a systematic review of randomized controlled trials.

OBJECTIVE: To systematically review the effectiveness of self-management training in type 2 diabetes. RESEARCH DESIGN AND METHODS: MEDLINE, Educational Resources Information Center (ERIC), and Nursing and Allied Health databases were searched for English-language articles published between 1980 and 1999. Studies were original articles reporting the results of randomized controlled trials of the effectiveness of self-management training in people with type 2 diabetes. Relevant data on study design, population demographics, interventions, outcomes, methodological quality, and external validity were tabulated. Interventions were categorized based on educational focus (information, lifestyle behaviors, mechanical skills, and coping skills), and outcomes were classified as knowledge, attitudes, and self-care skills; lifestyle behaviors, psychological outcomes, and quality of life; glycemic control; cardiovascular disease risk factors; and economic measures and health service utilization. RESULTS: A total of 72 studies described in 84 articles were identified for this review. Positive effects of self-management training on knowledge, frequency and accuracy of self-monitoring of blood glucose, self-reported dietary habits, and glycemic control were demonstrated in studies with short follow-up (<6 months). Effects of interventions on lipids, physical activity, weight, and blood pressure were variable. With longer follow-up, interventions that used regular reinforcement throughout follow-up were sometimes effective in improving glycemic control. Educational interventions that involved patient collaboration may be more effective than didactic interventions in improving glycemic control, weight, and lipid profiles. No studies demonstrated the effectiveness of self-management training on cardiovascular disease-related events or mortality; no economic analyses included indirect costs; few studies examined health-care utilization. Performance, selection, attrition, and detection bias were common in studies reviewed, and external generalizability was often limited. CONCLUSIONS: Evidence supports the effectiveness of self-management training in type 2 diabetes, particularly in the short term. Further research is needed to assess the effectiveness of self-management interventions on sustained glycemic control, cardiovascular disease risk factors, and ultimately, microvascular and cardiovascular disease and quality of life.

Adaptation, Psychological↗
PubMed2001

Association of physical activity and serum insulin concentrations in two populations at high risk for type 2 diabetes but differing by BMI.

OBJECTIVE: Physical activity and insulin sensitivity are related in epidemiological studies, but the consistency of this finding among populations that greatly differ in body size is uncertain. The present multiethnic epidemiological study examined whether physical activity was related to insulin concentrations in two populations at high risk for diabetes that greatly differ by location, ethnic group, and BMI. RESEARCH DESIGN AND METHODS: The study populations consisted of 2,321 nondiabetic Pima Indian men and women aged 15-59 years from Arizona and 2,716 nondiabetic men and women aged 35-54 years from Mauritius. Insulin sensitivity was estimated by mean insulin concentration (average of the fasting and postload insulin), and total (i.e., leisure and occupational) physical activity was assessed by questionnaire. RESULTS: Pima men and women who were more active had significantly (P < 0.05) lower mean insulin concentrations than those less active (BMI and age-adjusted means were 179 vs. 200 and 237 vs. 268 pmol/l). Similar findings were noted in Mauritian men and women (94 vs. 122 and 127 vs. 148 pmol/l). In both populations, activity remained significantly associated with mean insulin concentration controlled for age, BMI, waist-to-thigh or waist-to-hip ratio, and mean glucose concentrations. CONCLUSIONS: Physical activity was negatively associated with insulin concentrations both in the Pima Indians, who tend to be overweight, and in Mauritians, who are leaner. These findings suggest a beneficial role of activity on insulin sensitivity that is separate from any influence of activity on body composition.

Adolescent↗
PubMed2001

Temporal trends in BMI among adults with diabetes.

OBJECTIVE: Increasing obesity within the general population has been accompanied by rising rates of diabetes. The extent to which obesity has increased among people with diabetes is unknown, as are the potential consequences for diabetes outcomes. RESEARCH DESIGN AND METHODS: Community medical records (hospital and ambulatory) of all Rochester, Minnesota, residents aged > or =30 years who first met standardized research criteria for diabetes from 1970 to 1989 (n = 1,306) were reviewed to obtain data on BMI and related characteristics as of the diabetes identification date (+/-3 months). Vital status as of 31 December 1999 and date of death for those who died were obtained from medical records, State of Minnesota death tapes, and active follow-up. RESULTS: As of the identification date, data on BMI were available for 1,290 cases. Of the 272 who first met diabetes criteria in 1970-1974, 33% were obese (BMI > or =30), including 5% who were extremely obese (BMI > or =40). These proportions increased to 49% (P < 0.001) and 9% (P = 0.012), respectively, for the 426 residents who first met diabetes criteria in 1985-1989. BMI increased significantly with increasing calendar year of diabetes identification in multivariable regression analysis. Analysis of survival revealed an increased hazard of mortality for BMI > or =41, relative to BMI of 23-25 (hazard ratio 1.60, 95% CI 1.09-2.34, P = 0.016). CONCLUSIONS: The prevalence of obesity and extreme obesity among individuals at the time they first met criteria for diabetes has increased over time. This is disturbing in light of the finding that diabetic individuals who are extremely obese are at increased risk of mortality compared with their nonobese diabetic counterparts.

Adult↗
PubMed2000

Is diabetes associated with cognitive impairment and cognitive decline among older women? Study of Osteoporotic Fractures Research Group.

BACKGROUND: The long-term effect of type 2 diabetes on cognitive function is uncertain. OBJECTIVE: To determine whether older women with diabetes have an increased risk of cognitive impairment and cognitive decline. DESIGN: Prospective cohort study. SETTING: Four research centers in the United States (Baltimore, Md; Portland, Ore; Minneapolis, Minn; and the Monongahela Valley, Pennsylvania). PARTICIPANTS: Community-dwelling white women 65 years and older (n = 9679). MEASUREMENTS: Physician-diagnosed diabetes and other aspects of health history were assessed by interview. Three tests of cognitive function, the Digit Symbol test, the Trails B test, and a modified version of the Mini-Mental State Examination (m-MMSE), were administered at baseline and 3 to 6 years later. Change in cognitive function was defined by the change in the score for each test. Major cognitive decline was defined as the worst 10th percentile change in the score for each test. RESULTS: Women with diabetes (n = 682 [7.0%]) had lower baseline scores than those without diabetes on all 3 tests of cognitive function (Digit Symbol and Trials B tests, P<.01; m-MMSE, P = .03) and experienced an accelerated cognitive decline as measured by the Digit Symbol test (P<.01) and m-MMSE (P = .03). Diabetes was also associated with increased odds of major cognitive decline as determined by scores on the Digit Symbol (odds ratio = 1.63; 95% confidence interval, 1.20-2.23) and Trails B (odds ratio, 1.74; 95% confidence interval, 1.27-2.39) tests when controlled for age, education, depression, stroke, visual impairment, heart disease, hypertension, physical activity, estrogen use, and smoking. Women who had diabetes for more than 15 years had a 57% to 114% greater risk of major cognitive decline than women without diabetes. CONCLUSION: Diabetes is associated with lower levels of cognitive function and greater cognitive decline among older women.

Aged↗
PubMed2000

Evaluation of simple indices of insulin sensitivity and insulin secretion for use in epidemiologic studies.

The metabolic characteristics of type 2 diabetes, insulin resistance, and diminished insulin secretion are costly to measure directly. To evaluate the utility of several simple indices derived from insulin and glucose measurements, the indices were examined from 1982 to 1997 with respect to correlation with more sophisticated measures of insulin sensitivity and secretion in Pima Indians in the Gila River Indian Community of Arizona. Ability to predict the incidence of diabetes in 1,731 persons was also examined. Indices were calculated from fasting and 2-hour glucose (G0, G120) and insulin (I0, I120) concentrations obtained during an oral glucose tolerance test. Fasting serum insulin concentration and the insulin sensitivity index (10(4)/(I0 x G0)) each showed a moderate correlation with the estimate of insulin sensitivity derived from the hyperinsulinemic-euglycemic clamp (absolute value r approximately 0.60). They also strongly predicted the incidence of diabetes (incidence rate ratio comparing the most and least insulin-resistant tertile groups approximately 3.0). Corrected insulin response (I120/(G120 x (G120 - 70))) was modestly correlated with insulin secretion as measured by an intravenous glucose tolerance test (r = 0.35). Impaired insulin secretion assessed by this index predicted incidence of diabetes, particularly after control for insulin sensitivity index (incidence rate ratio = 1.6). Thus, simple indices of insulin sensitivity and secretion may be reasonable surrogates for more sophisticated measures in epidemiologic studies.

Adult↗
PubMed2000

Diabetes--a common, growing, serious, costly, and potentially preventable public health problem.

An estimated 135 million people worldwide had diagnosed diabetes in 1995, and this number is expected to rise to at least 300 million by 2025. The number of people with diabetes will increase by 42% (from 51 to 72 million) in industrialized countries between 1995 and 2025 and by 170% (from 84 to 228 million) in industrializing countries. Several potentially modifiable risk factors are related to diabetes, including insulin resistance, obesity, physical inactivity and dietary factors. Diabetes may be preventable in high-risk groups, but results of ongoing clinical trials are pending. Several efficacious and economically acceptable treatment strategies are currently available (control of glycemia, blood pressure, lipids; early detection and treatment of retinopathy, nephropathy, foot-disease; use of aspirin and ACE inhibitors) to reduce the burden of diabetes complications. Diabetes is a major public health problem and is emerging as a pandemic. While prevention of diabetes may become possible in the future, there is considerable potential now to better utilize existing treatments to reduce diabetes complications. Many countries could benefit from research aimed at better understanding the reasons why existing treatments are under-used and how this can be changed.

Costs and Cost Analysis↗