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R L Hanson

Publications and source records attributed to R L Hanson.

At least 19 recordsLinked to original sources
PubMed1995

Early and late insulin response as predictors of NIDDM in Pima Indians with impaired glucose tolerance.

Risk factors predicting deterioration to diabetes mellitus were examined in 181 subjects with impaired glucose tolerance. Fifty-seven subjects had impaired glucose tolerance on one occasion followed by normal glucose tolerance at a repeat oral glucose tolerance test, and 124 subjects had impaired glucose tolerance on two successive oral glucose tolerance tests. Subjects were followed for a median period of 5.0 years (range 1.0-17.2). The age- and sex-adjusted cumulative incidence of diabetes at 10 years of follow-up was higher in subjects who had impaired glucose tolerance on both tests (70%) than in those whose glucose tolerance was normal at the repeat test (53%), [rate ratio (RR) = 1.6, 95% confidence intervals (CI) = 1.0-2.5]. Proportional hazards analyses were used to identify baseline risk factors (measured at the repeat oral glucose tolerance test) for subsequent diabetes, and incidence rate ratios were calculated for the 90th percentile compared with the 10th percentile of each continuous variable for the whole group. In all subjects, in separate models, higher body mass index [RR = 2.0, 95% CI = 2.2-9.9], high fasting serum insulin concentrations [RR = 2.4, 95% CI = 1.4-4.2], and low early insulin response [RR = 0.5, 95% CI = 0.3-0.8] 30 min after a glucose load were significant predictors for deterioration to diabetes. In a multivariate analysis which controlled for age and sex, 120-min post-load glucose, fasting insulin and late insulin response predicted diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Diabetic nephropathy: a risk factor for diabetes mellitus in offspring.

Both non-insulin-dependent diabetes mellitus and diabetic nephropathy show familial aggregation. If diabetes and renal disease have independent determinants (genetic or otherwise), offspring of parents with diabetic renal disease should have a similar risk of diabetes to those offspring of parents with diabetes alone. To test this hypothesis, the prevalence of diabetes was examined in a population-based pedigree study in Pima Indian offspring of three mutually exclusive parental types: 1) diabetic with renal disease, 2) diabetic, but without renal disease and 3) non-diabetic. Among offspring of one diabetic parent and one non-diabetic parent (n = 320) the prevalence of diabetes at ages 15-24 years and 25-34 years was 0% and 11%, respectively if the diabetic parent did not have renal disease compared with 6% and 28% respectively if the diabetic parent did have renal disease. Corresponding rates for offspring of two diabetic parents (n = 121) were 10% and 17%, respectively if neither parent had renal disease compared with 30% and 50%, respectively if one parent did have renal disease. The presence of renal disease in a parent with diabetes relative to diabetes alone was associated with 2.5 times the odds of diabetes (95% confidence interval 1.4-4.3) in the offspring controlled for age, age at onset of parental diabetes and diabetes in the other parent using logistic regression. These findings provide support for parental diabetic renal disease, independent of age at onset of parental diabetes, conferring an increased risk for diabetes in the offspring.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
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↗
PubMed1995

Incidence and determinants of elevated urinary albumin excretion in Pima Indians with NIDDM.

OBJECTIVE: To examine the incidence and determinants of elevated urinary albumin excretion in Pima Indians with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: The incidence of elevated urinary albumin excretion (> or = 30 mg albumin/g creatinine) and its relationship with baseline characteristics was determined in 456 Pima Indians > or = 15 years old with NIDDM who were followed for up to 11.6 years (median 4.7 years). RESULTS: Of these 456 subjects, 192 (42%; 58 men, 134 women) developed elevated urinary albumin excretion, 172 of whom (90%) were within the microalbuminuric range (30-299 mg/g). The incidence of elevated urinary albumin excretion was related to retinopathy, type, of diabetes treatment, longer duration of diabetes, lower body mass index, and higher values of mean arterial pressure, HbA1, and fasting and 2-h postload plasma glucose concentration at the baseline examination, but not to sex. A relationship with cholesterol was found in durations of diabetes of > or = 10 years. The cumulative incidence of elevated albumin excretion was 17% after 5 years of NIDDM. CONCLUSIONS: The incidence of elevated urinary albumin excretion in Pima Indians with NIDDM is at least as high as that reported previously in insulin-dependent diabetes mellitus, and its major determinants are the same as those shown previously to predict the development of more advanced renal disease in this population.

Adolescent↗
PubMed1995

Comparison of body size measurements as predictors of NIDDM in Pima Indians.

OBJECTIVE--To determine and compare the abilities of various anthropometric measurements to predict the development of non-insulin-dependent diabetes mellitus (NIDDM) in Pima Indian men and women. RESEARCH DESIGN AND METHODS--A total of 290 male and 443 female Pima Indians were followed for up to 6 years for the development of NIDDM. A proportional hazards analysis was used to assess the ability of anthropometric measurements evaluated at baseline to predict NIDDM. Receiver operating characteristic (ROC) curves were used to compare individual variables in predicting NIDDM. RESULTS--In separate models controlled for age and sex, body mass index (BMI), waist circumference, thigh circumference, waist-to-thigh ratio (WTR), weight, and percentage body fat (PBF) estimated by bioelectric resistance each predicted NIDDM, which developed in 30 men and 52 women. The highest incidence rate ratios (IRRs; for 1 SD of a variable) were for WTR in men and for PBF in women, although the confidence interval (CI) for PBF was wide. In stepwise analyses, WTR was the most significant predictor in men (IRR for 1 SD = 1.58, 95% CI = 1.20-2.07), and BMI was the most significant predictor in women (IRR for 1 SD = 1.65, 95% CI = 1.29-2.11). However, by ROC analyses, thigh circumference was the only variable significantly worse than WTR in men or BMI in women at predicting NIDDM. CONCLUSIONS-- Measurements such as waist circumference, WTR, weight, and BMI may be useful as more complicated measurements, such as PBF by bioelectrical resistance, for identifying groups of individuals whose body habitus places them at high risk of developing NIDDM.

Adolescent↗
PubMed1995

Segregation analysis of non-insulin-dependent diabetes mellitus in Pima Indians: evidence for a major-gene effect.

Non-insulin-dependent diabetes mellitus (NIDDM) has a high prevalence in Pima Indians. The disorder is familial, but the extent to which genetic factors are involved in its etiology is largely unknown. Segregation analysis was used to determine whether familial aggregation of NIDDM in this population could reflect the action of a single major gene. The analysis included 2,697 subjects from 653 nuclear families in which both parents and at least one offspring had been examined in the course of a longitudinal epidemiological study. The REGTL program of the SAGE package was used to fit models in which age at onset of NIDDM is transmitted from parent to offspring under the unified model for segregation analysis. Likelihood-ratio tests were used to test hypotheses related to genetic transmission. The hypothesis of no major effect was strongly rejected (P < .01), as was that of no transmission of the major effect (P < .01). Mendelian transmission was not rejected (P = .91). Similar results were obtained when covariates for obesity and birth cohort were added to the models and when a power transformation of age at onset was estimated. A strong effect of birth cohort with earlier age at onset in the later born cohorts was observed (P < .01). The findings are consistent with the hypothesis that a major gene influences the risk for NIDDM in Pima Indians by affecting age at onset. The expression of this gene may depend on environmental factors that have become more prevalent in recent-birth cohorts.

Adolescent↗
PubMed1994

Site-specific enzymatic hydrolysis of taxanes at C-10 and C-13.

The production of large amounts of paclitaxel for use as an anticancer treatment has been a challenging problem because of the low concentration of the compound in yew trees and its occurrence as part of a mixture of other taxanes. Two novel enzymes were isolated to facilitate the production of 10-deacetylbaccatin III, a precursor used for semisynthesis of paclitaxel and analogs. A strain of Nocardioides albus (SC13911) was isolated from soil and found to produce an extracellular enzyme that specifically removed the C-13 side chain from paclitaxel, cephalomannine, 7-beta-xylosyltaxol, 7-beta-xylosyl-10-deacetyltaxol, and 10-deacetyltaxol. The enzyme was purified to near homogeneity to give a polypeptide with 47,000 M(r) on a sodium dodecyl sulfate gel. A strain of Nocardioides luteus (SC13912) isolated from soil was found to produce an intracellular 10-deacetylase that removed the 10-acetate from baccatin III and paclitaxel. The 10-deacetylase was purified to give a polypeptide with 40,000 M(r) on a sodium dodecyl sulfate gel. Treatment of extracts prepared from a variety of yew cultivars with the C-13-deacylase and C-10-deacetylase converted a complex mixture of taxanes primarily to 10-deacetylbaccatin III and increased the amount of this key precursor by 4-24 times.

Bridged Bicyclo Compounds↗
PubMed1994

Familial and metabolic factors related to blood pressure in Pima Indian children.

High blood pressure, abnormal glucose tolerance, and obesity are frequently associated with each other, but the mechanism of these associations is poorly understood. Studying them in children may help in understanding the pathogenesis of hypertension. Blood pressure, height, weight, and plasma glucose and serum insulin concentrations during a 75-g oral glucose tolerance test were measured in 1,698 Pima Indian children aged 6-17 years who participated in an ongoing epidemiologic study. Weight relative to height was used as an index of obesity. The parents of many of the children were also examined. Fasting and 2-hour glucose and insulin concentrations, adjusted for age, sex, and relative weight, were positively related to systolic blood pressure but not to diastolic blood pressure. Relative weight, 2-hour glucose, and fasting insulin concentrations were independently and significantly associated with systolic blood pressure in a stepwise regression analysis that included age and sex. After parental hypertension was taken into account, maternal but not paternal non-insulin-dependent diabetes mellitus, controlled for the child's relative weight and glucose and insulin concentrations, was significantly associated with higher blood pressure in children. The stronger association with maternal diabetes suggests a greater sharing of environmental factors between mother and child than between father and child, but familial similarities in obesity and glucose and insulin concentrations, the diabetic intrauterine milieu, and shared environmental factors probably all contribute to this association.

Adolescent↗
PubMed1994

Comparison of tests for glycated haemoglobin and fasting and two hour plasma glucose concentrations as diagnostic methods for diabetes.

OBJECTIVE: To compare the ability of tests measuring two hour plasma glucose, fasting plasma glucose, and glycated haemoglobin concentrations in predicting the specific microvascular complications of non-insulin dependent diabetes mellitus. DESIGN: Cross sectional and longitudinal analysis of the relation between complications and concomitant results of the three tests. SETTING: Gila River Indian Community, Arizona. SUBJECTS: Pima Indians (cross sectional, n = 960), aged 25 years or above who were not receiving insulin or oral hypoglycaemic treatment at the baseline examination. MAIN OUTCOME MEASURES: Development of retinopathy and nephropathy. RESULTS: Cross sectionally, frequency distributions of logarithms of the three sets of results were bimodal, with the prevalence of retinopathy and nephropathy being, respectively, 12.0-26.7 and 3.9-4.2 times as high above as below cut off points which minimised overlap (two hour plasma glucose concentration 12.6 mmol/l; fasting plasma glucose concentration 9.3 mmol/l; glycated haemoglobin (HbA1c) concentration 7.8%). Longitudinally, each of the three measures of glycaemia significantly predicted the development of retinopathy (P < 0.0001) and nephropathy (P < 0.05). Receiver operating characteristic curves showed that two hour plasma glucose concentration was superior to fasting plasma glucose concentration (P < 0.05) for prevalent cases of retinopathy, but otherwise no variable had a significant advantage for detecting incident or prevalent cases of either complication. CONCLUSIONS: These findings suggest that determination of glycated haemoglobin or fasting plasma glucose concentrations alone may be acceptable alternatives to measuring glucose concentration two hours after challenge with 75 g glucose for the diagnosis of diabetes.

Adult↗
PubMed1994

Birth weight and non-insulin dependent diabetes: thrifty genotype, thrifty phenotype, or surviving small baby genotype?

OBJECTIVE: To determine the prevalence of diabetes in relation to birth weight in Pima Indians. DESIGN: Follow up study of infants born during 1940-72 who had undergone a glucose tolerance test at ages 20-39 years. SETTING: Gila River Indian community, Arizona. SUBJECTS: 1179 American Indians. MAIN OUTCOME MEASURE: Prevalence of non-insulin dependent diabetes mellitus (plasma glucose concentration > or = 11.1 mmol/l two hours after ingestion of carbohydrate). RESULTS: The prevalence was greatest in those with the lowest and highest birth weights. The age adjusted prevalences for birth weights < 2500 g, 2500-4499 g, and > or = 4500 g were 30%, 17%, and 32%, respectively. When age, sex, body mass index, maternal diabetes during pregnancy, and birth year were controlled for, subjects with birth weights < 2500 g had a higher rate than those with weights 2500-4499 g (odds ratio 3.81; 95% confidence interval 1.70 to 8.52). The risk for subsequent diabetes among higher birthweight infants (> or = 4500 g) was associated with maternal diabetes during pregnancy. Most diabetes, however, occurred in subjects with intermediate birth weights (2500-4500 g). CONCLUSIONS: The relation of the prevalence of diabetes to birth weight in the Pima Indians is U shaped and is related to parental diabetes. Low birth weight is associated with non-insulin dependent diabetes. Given the high mortality of low birthweight infants selective survival in infancy of those genetically predisposed to insulin resistance and diabetes provides an explanation for the observed relation between low birth weight and diabetes and the high prevalence of diabetes in many populations.

Adult↗
PubMed1994

Crystallization and quaternary structure analysis of the NAD(+)-dependent leucine dehydrogenase from Bacillus sphaericus.

The NAD(+)-dependent leucine dehydrogenase from Bacillus sphaericus has been crystallized by the hanging drop method of vapour diffusion, using ammonium sulphate as the precipitant. The crystals belong to the tetragonal system and are in space group I4, with unit cell dimensions of a = b = 138.4 A and c = 121.8 A. Considerations of the values of Vm, the space group symmetry and an analysis of a self-rotation function calculated on a preliminary data set collected to 3 A resolution show that the asymmetric unit contains a dimer with the twofold axis perpendicular to the crystallographic four fold, indicating that the quaternary structure of this enzyme is octameric. Leucine dehydrogenase belongs to a superfamily of amino acid dehydrogenases which display considerable differences in amino acid specificity and elucidation of its three-dimensional structure should enable the molecular basis of this differential specificity to be examined in detail.

Amino Acid Oxidoreductases↗
PubMed1994

Decreasing incidence and prevalence of rheumatoid arthritis in Pima Indians over a twenty-five-year period.

OBJECTIVE: To evaluate temporal trends in the incidence of rheumatoid arthritis (RA). METHODS: Incident cases of RA were identified among a population-based cohort of Pima Indians in Arizona over the period 1965-1990. RESULTS: Among 2,894 subjects, 78 incident cases of RA were identified. The age-adjusted incidence declined by 55% in men (Ptrend = 0.225), and by 57% in women (Ptrend = 0.017) after controlling for oral contraceptive or estrogen use and for pregnancy experience. During the same period, age-adjusted prevalence rates of active RA decreased by 29% in men (Ptrend = 0.63) and by 40% in women (Ptrend = 0.02). Fewer than 17% of subjects with known RA were taking slow-acting antirheumatic drugs (SAARDs) in 1990. CONCLUSION: The decrease in incidence and prevalence of RA in this population over such a short period implicates the involvement of an environmental factor(s), other than exogenous estrogens, in the pathogenesis of the disease. However, the possibility that the observed decrease might be explained by an increased use of SAARDs in subjects with RA cannot be excluded.

Adolescent↗
PubMed1994

A cross-sectional and longitudinal comparison of the Rome criteria for active rheumatoid arthritis (equivalent to the American College of Rheumatology 1958 criteria) and the American College of Rheumatology 1987 criteria for rheumatoid arthritis.

OBJECTIVE: To compare the diagnostic properties of the Rome 1961 criteria for active rheumatoid arthritis (RA) and the American College of Rheumatology (ACR; formerly, the American Rheumatism Association) 1987 criteria for RA with regard to their ability to classify, diagnose, and predict outcome in RA. METHODS: Analysis of cross-sectional and longitudinal data from repeated health examinations and review of clinical records of 3,509 Pima Indians followed up from January 1966 to December 1990. RESULTS: The ACR 1987 criteria identified approximately 50% of the cases identified by the Rome 1961 criteria, in both cross-sectional and longitudinal analyses. The ACR 1987 criteria were better predictors of subsequent development of a clinically supported diagnosis and treatment with slow-acting antirheumatic drugs (both P < 0.001), but were less sensitive than the Rome 1961 criteria for detecting cases for which there already was a clinically supported diagnosis (P < 0.001). CONCLUSION: In a population-based analysis, the ACR 1987 criteria are less sensitive for detecting clinical disease, but predict a clinically more severe prognosis, compared with the Rome 1961 criteria. The sensitivity of both sets of criteria to identify clinical disease is improved if multiple examinations or inactive disease are taken into account.

Arizona↗
PubMed1994

Glucose, insulin concentrations and obesity in childhood and adolescence as predictors of NIDDM.

Metabolic abnormalities antedate the development of non-insulin-dependent diabetes mellitus (NIDDM) by some years. How these metabolic abnormalities relate to the genetic component of the disease and to the subsequent prediction of diabetes is unknown. The present study was designed to examine the association of parental diabetes with relative weight, fasting and 2-h plasma glucose and fasting and 2-h serum insulin in childhood, and to identify which of these variables were most predictive of subsequent NIDDM. Subjects comprised 1258 Pima Indians aged 5-19 years with normal glucose tolerance participating in a longitudinal population-based study. Age-sex-adjusted values of relative weight, fasting and 2-h glucose and fasting and 2-h insulin were positively associated with parental diabetes. Only one of 138 subjects with two non-diabetic parents developed diabetes. Among 1120 subjects with at least one diabetic parent, 101 (9.0%) developed diabetes during a mean follow up of 8.4 years. Fasting insulin was a significant predictor of diabetes, but did not add to the predictive value of relative weight. Relative weight and 2-h and fasting plasma glucose were the variables most predictive of NIDDM in childhood and adolescence. Against a background of parental diabetes, high fasting insulin concentrations predict diabetes, compatible with the hypothesis that insulin resistance is an early metabolic abnormality leading to NIDDM. In this study, however, its predictive power did not add significantly to that of relative weight, with which it was correlated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗