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K M Narayan

Publications and source records attributed to K M Narayan.

65 records · Page 4Linked to original sources
PubMed1995

The U-shaped association between body mass index and mortality: relationship with weight gain in a Native American population.

In order to determine whether weight loss explains high mortality rates in those with a low body mass index (BMI), the relationships between BMI, rate of weight gain and mortality were examined in Pima Indians. Subjects were 814 diabetic and 1814 nondiabetic participants in a longitudinal survey who had at least two examinations after age 20. Median duration of follow-up was 8.1 (range 0.03-25.1) years. BMI showed a U-shaped relationship with mortality rates in men with the lowest rates in the 30-35 kg/m2 category; an inverse relationship was seen in women. Subjects who were losing weight had higher mortality rates than those who were gaining. However, excess mortality among the lightest subjects was present among those who were gaining weight. Among nondiabetic subjects, the mortality ratio (MR) for BMI < 25 kg/m2 compared with 30-35 kg/m2 was 1.5 [95% confidence interval (CI) 1.0-2.2] unadjusted for weight gain, while the adjusted MR was 1.3 [95% CI 0.9-1.9]. Weight loss, which may reflect underlying illness, is associated with high mortality rates in Pima Indians but does not fully account for the high mortality in the lightest individuals.

Adult↗
PubMed1995

Rate of weight gain, weight fluctuation, and incidence of NIDDM.

The relationships of rate of weight gain and weight fluctuation to incidence of non-insulin-dependent diabetes mellitus (NIDDM) were examined in Pima Indians. The 1,458 subjects were participants in a prospective study with examinations approximately every 2 years. Rate of weight gain was defined as the slope of the regression line of weight with time for two or more consecutive examinations > or = 2 years apart and weight fluctuation as the root-mean-square departure from this line for four examinations. Among men, incidence of NIDDM was strongly and significantly related to rate of weight gain (e.g., age-adjusted incidence = 56.7/1,000 person-years in those with weight gain > or = 3 kg/year and 16.9/1,000 person-years for those losing weight [Ptrend < 0.01]). In women, weight gain was significantly related to diabetes incidence only in those who were not initially overweight (body mass index < 27.3 kg/m2). In contrast to the relationship with weight gain, weight fluctuation was not associated with incidence of diabetes in either sex. These findings suggest that weight control in overweight individuals may be a more effective strategy for prevention of NIDDM in men than in women, whereas prevention of obesity may prevent diabetes in both sexes. Concern about a diabetogenic effect of weight fluctuation should not deter weight-control efforts.

Adult↗
PubMed1995

Familial relationships between obesity and NIDDM.

Obesity and family history of diabetes are both risk factors for non-insulin-dependent diabetes mellitus (NIDDM), but it has been proposed that lean individuals with NIDDM have a greater load of diabetes susceptibility genes. If this is the case, one might expect a high prevalence of NIDDM in relatives of diabetic individuals with a low body mass index (BMI). Among Pima Indians participating in an epidemiological study, prevalence of NIDDM was evaluated in relation to BMI of a diabetic parent or to the average parental BMI when both parents had diabetes in 1,535 offspring from 547 families. Prevalence of NIDDM was also evaluated in relation to BMI of a randomly selected index diabetic sibling in 1,722 siblings from 721 families. NIDDM was diagnosed by an oral glucose tolerance test. Compared with offspring of diabetic parent(s) at the 25th percentile of BMI, the odds ratio (OR) for diabetes in offspring of diabetic parents at the 75th percentile was 0.6 (95% confidence interval [CI] 0.5-0.7), adjusted for age, sex, BMI in offspring, number of diabetic parents, and age at onset of diabetes and sex of the diabetic parent(s). In the analysis according to BMI in a diabetic sibling, the corresponding OR was 0.8 (95% CI 0.6-0.9). Risk ratios were only modestly higher when the analysis was restricted to relatives of subjects whose BMI had been determined before the onset of diabetes. NIDDM in the presence of a low BMI is more strongly familial than that at a higher BMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Preventing non-insulin-dependent diabetes.

Many risk factors for non-insulin-dependent diabetes mellitus (NIDDM), such as obesity, physical inactivity, and high-fat diet, can potentially be modified. Furthermore, some of the metabolic abnormalities, such as insulin resistance and impaired glucose tolerance, that predict diabetes can be improved by behavior modification and drug treatment. Thus, at least to some extent, NIDDM may be preventable. Several small clinical trials have addressed the hypothesis that NIDDM can be prevented by dietary modification, physical activity, or drug treatment. Some studies suggest a preventive effect, but the conclusions are limited by considerations of sample size, randomization, or intensity of the interventions. Consequently, the hypothesis that NIDDM is preventable requires further testing.

Behavior Therapy↗
PubMed1994

Prevention of non-insulin-dependent diabetes mellitus.

Non-insulin-dependent diabetes mellitus (NIDDM) is a chronic disease which may take several years to develop, presumably starting in most cases with genetic susceptibility. Development of NIDDM is influenced by obesity and physical inactivity. As these risk factors can be altered by behavioral modification, and some of the physiologic abnormalities predicting diabetes, such as insulin resistance and impaired glucose tolerance, can be improved by behavioral modification and with drugs, NIDDM is potentially preventable. This potential needs to be demonstrated by randomized clinical trials.

Diabetes Mellitus, Type 2↗
PubMed1994

Comparison of World Health Organization and National Diabetes Data Group procedures to detect abnormalities of glucose tolerance during pregnancy.

OBJECTIVE: To compare the one-step procedure proposed by the World Health Organization (WHO) with the two-step procedure proposed by the National Diabetes Data Group (NDDG) for the identification of abnormalities of glucose tolerance during pregnancy. RESEARCH DESIGN AND METHODS: One hundred twenty-seven non-diabetic Pima Indian women had a 75-g 2-h glucose tolerance test (WHO criteria). Those with an elevated 1-h glucose concentration (> or = 7.8 mmol/l) were referred for a 100-g 3-h glucose tolerance test (National Diabetes Data Group criteria). The effectiveness of the two test procedures was determined by comparing the frequency of macrosomia and cesarean section as outcomes of pregnancy. RESULTS: Of 42 women with 1-h plasma glucose concentrations > or = 7.8 mmol/l, 13 had no 100-g test, 27 had a normal test, and 2 had an abnormal test. Both women (100%) with abnormal two-step 100-g tests also had abnormal one-step 75-g tests, but only 2 of the 11 women (18%) with an abnormal one-step test had an abnormal two-step test. Sixteen of the 127 women delivered babies weighing > or = 4,000 g. Six of these women (38%) were correctly identified as abnormal using the one-step test and one (6%) using the two-step test. Of seven women delivering by cesarean section, four (57%) had abnormal one-step tests, but none had an abnormal two-step test. CONCLUSIONS: The one-step WHO test for glucose tolerance during pregnancy was abnormal in a greater percentage of women with adverse outcomes than the more cumbersome two-step NDDG test. The one-step test has the added advantage of being directly comparable to the standard glucose tolerance test used in nonpregnant women.

Arizona↗
PubMed1992

Development of indicators for quality assurance in public health medicine.

OBJECTIVES: To develop structure, process, and outcome indicators within a quality rating index for audit of public health medicine. DESIGN: Development of an audit matrix and indicator of quality through a series of group discussions with public health physicians, from which self administered weighted questionnaires were constructed by a modified Delphi technique. SETTING: Five Scottish health boards. SUBJECTS: Public health physicians in the five health boards. MAIN MEASURES: Indicators of quality and a quality rating index for seven selected service categories for each of seven agreed roles of public health medicine: assessment of health and health care needs in information services, input into managerial decision making in health promotion, fostering multisectoral collaboration in environmental health services, health service research and evaluation for child services, lead responsibility for the development and/or running of screening services, and public health medicine training and staff development in communicable disease. RESULTS: Indicators in the form of questionnaires were developed for each topic. Three types of indicator emerged: "global," "restricted," and "specific." A quality rating index for each topic was developed on the basis of the questionnaire scores. Piloting of indicators showed that they are potentially generalisable; evaluation of the system is under way across all health boards in Scotland. CONCLUSION: Measurable indicators of quality for public health medicine can be developed.

Data Collection↗
PubMed1992

Measles, mumps, rubella antibody surveillance: pilot study in Grampian, Scotland.

The prevalence of measles, mumps and rubella antibodies for ages over six months was obtained using a stratified random sample of stored sera submitted in 1988 prior to the implementation of MMR vaccine. Besides reflecting the different vaccination policies for the three viruses the results showed that males display earlier sero-conversion for all three infections and a higher proportion of older males are susceptible. Two-thirds of children aged 6-15 months had antibodies to measles, the majority of which were apparently vaccine induced. However, the possibility that a few children contract natural measles before the recommended age for MMR vaccine cannot be ruled out. A system of continuous sero-surveillance to monitor the effect of MMR vaccine is suggested.

Adolescent↗
PubMed1990

Cardiovascular risk factors and health behavior: some preliminary findings from the Cardiovascular Diseases and Alimentary Comparison Study.

This paper presents some preliminary findings from one particular Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study data collection center. The population and the environment of the Western Isles, Scotland, from where the subjects were drawn, are described. The methodology was as according to the CARDIAC Study protocol. The results show that in this population there is a high mean serum total cholesterol level, a high prevalence of smokers, and a high mean body mass index. However, knowledge, attitudes, and reported behavior change regarding diet were encouraging. Much further data processing work remains to be done.

Adult↗
PubMedDate not supplied

Family and genetic studies of indices of insulin sensitivity and insulin secretion in Pima Indians.

BACKGROUND: The present analyses were conducted to examine the extent to which insulin sensitivity and insulin secretion, assessed using simple indices derived from an oral glucose tolerance test, are influenced by genetic factors, and to assess whether these genetic factors overlap with those influencing susceptibility to type 2 diabetes in Pima Indians. METHODS: Indices calculated from fasting and 2-h post-load insulin (I(0), I(120)) and glucose (G(0), G(120)) concentrations included insulin sensitivity index [ISI(0)=10(4)/(I(0).G(0))] and corrected insulin response [CIR(120)=I(120)/[G(120).(G(120)-70 mg/dl)]]. Heritability (h(2)) was determined using variance components methods in 1421 non-diabetic individuals from 446 sibships. Among 595 individuals in 186 sibships, genome-wide quantitative trait linkage analyses of ISI(0) and CIR(120) were conducted and affected-sibling analyses of diabetic siblings stratified by prediabetic measurements of ISI(0) and CIR(120) were also performed. RESULTS: Both ISI(0) (h(2)=0.37+/-0.06) and CIR(120) (h(2)=0.25+/-0.07) were moderately heritable. Modest evidence for linkage with CIR(120) (logarithm of odds (LOD)=1.6) was observed on chromosome 1q in a region previously shown to have linkage with young-onset diabetes in Pimas. When diabetic siblings were stratified by CIR(120), evidence for linkage in this region was strongest (LOD=1.5) among those with a low CIR(120). Additional regions with modest evidence for linkage with ISI(0) were observed on chromosomes 9p (LOD=2.0) and 14p (LOD=1.7). CONCLUSIONS: The present analyses suggest that insulin sensitivity and insulin secretion are influenced by genetic factors in Pima Indians. The linkage analyses suggest that the putative diabetes-susceptibility gene on chromosome 1q affects insulin secretion. Published in 2001 by John Wiley & Sons, Ltd.

Arizona↗