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Biomedical subjects

B E Klein

Publications and source records attributed to B E Klein.

At least 199 records · Page 11Linked to original sources
PubMed1992

Gallium-67 distribution in a man with a decrease in both transferrin and hepatic gallium-67 concentration.

A patient with reduced transferrin concentration had a 67Ga scintigram that showed uptake in a peritoneal abscess, pericarditis and pleural effusion but only faint liver uptake. Gallium-67 activity was measured in liver, lung, muscle and plasma samples obtained at autopsy. The percent injected dose/kg for liver and plasma samples was considerably lower than previously reported while that in muscle and lung tissues values were comparable to prior data. In this patient, sites on transferrin available to bind 67Ga were reduced from the normal 40 microM to 5.2 microM; this in turn increased the concentration of radiogallate from 1% to 7%. This elevated free activity increased 67Ga excretion and reduced the amount of 67Ga*transferrin species. These results and those of previous studies suggest that liver uptake is slower than abscess uptake and more sensitive to concentration of 67Ga*transferrin. Iron status is an important facet of the interpretation of 67Ga scintigrams.

Abscess↗
PubMed1992

The prevalence and incidence of lower extremity amputation in a diabetic population.

OBJECTIVE: To describe the incidence of lower extremity amputations and sores or ulcers and investigate risk factors for these complications. DESIGN: Cohort. SETTING: Primary care. PARTICIPANTS: Population-based sample (N = 1210) of younger-onset diabetic persons (diagnosed before age 30 years and taking insulin) and a stratified random sample (N = 1780) of older-onset diabetic persons (diagnosed after age 30 years). Baseline and 4-year follow-up examinations were completed by 996 and 891 younger-onset persons, respectively, and by 1370 and 987 older-onset persons, respectively. MAIN OUTCOME MEASURES: Amputations and sores or ulcers of the lower extremities. RESULTS: Four-year incidence of amputations was 2.2% in both groups. Incidence of sores or ulcers was 9.5% in younger-onset and 10.5% in older-onset persons. In younger-onset persons, significant risk factors for amputation with odds ratios (and 95% confidence intervals) include age, 2.0 for 10 years (1.2 to 3.1), history of sores or ulcers, 10.5 (3.7 to 29.8), diastolic blood pressure, 2.1 for 10 mm Hg (1.3 to 3.5), and pack-years smoked, 1.3 for 10 years (1.0 to 1.6). Risk factors for sores or ulcers include glycosylated hemoglobin, 1.6 for 2% (1.3 to 2.0), retinopathy, 1.3 for two steps (1.1 to 1.6), and current smoking, 2.3 (1.0 to 5.6). In older-onset persons, risk factors for amputation are history of sores or ulcers, 4.6 (1.7 to 12.2), proteinuria, 4.3 (1.6 to 11.5), glycosylated hemoglobin, 1.5 for 2% (1.0 to 2.2), sex, 2.8 for males (1.0 to 7.5), and duration of diabetes, 1.8 for 10 years (1.0 to 3.2). For sores or ulcers, risk factors are glycosylated hemoglobin, 1.6 for 2% (1.3 to 2.0), duration, 1.5 for 10 years (1.0 to 2.1), proteinuria, 2.2 (1.1 to 4.3), and diastolic blood pressure, 0.8 for 10 mm Hg (0.6 to 1.0). CONCLUSIONS: Several factors offer potential for modification for the prevention of amputations but require further study. These include blood pressure, glycosylated hemoglobin, and smoking.

Adolescent↗
PubMed1992

Intraocular pressure in an American community. The Beaver Dam Eye Study.

The Beaver Dam Eye Study is a population-based study of age-related eye diseases in persons 43-86 yr of age. Applanation tonometry was done on all study subjects. Mean intraocular pressure (IOP) increased significantly with age. Mean IOP differed little between the sexes and was not significantly different after age adjustment (in right eyes of 2721 women, it was 15.5 mm Hg, and in right eyes of 2135 men, it was 15.3 mm Hg). There was an association of IOP with systolic and diastolic blood pressures, body mass index, hematocrit, serum glucose, glycohemoglobin, cholesterol level, pulse, nuclear sclerosis, season, and time of day of measurement. These data confirm that, in a general population, IOP is associated with important systemic and ocular characteristics. Those characteristics should be considered in further research on determinants of IOP.

Adult↗
PubMed1992

Microalbuminuria in a population-based study of diabetes.

The prevalence of microalbuminuria in younger-onset diabetic participants in a large population-based study of diabetic retinopathy was determined, and the relationships of microalbuminuria to blood pressure and other risk factors were investigated. Using an agglutination inhibition test (AlbuScreen), the frequency of microalbuminuria was 21.2%. To evaluate the association of several characteristics with the presence of microalbuminuria, multivariate models based on logistic regression were developed. Microalbuminuria was associated with having higher systolic or diastolic blood pressure and higher glycosylated hemoglobin. These findings give further impetus to efforts to reduce controllable risk factors in younger-onset diabetic persons.

Adult↗
PubMed1991

The validity of self-reported and surrogate-reported cataract and age-related macular degeneration in the Beaver Dam Eye Study.

The validity of reported ocular disease was investigated in a population-based epidemiologic study of persons aged 43-86 years residing in Beaver Dam, Wisconsin. In a telephone survey conducted from September 1987 through May 1988, histories of cataract and age-related macular degeneration were obtained from the subject for 2,155 cases and from a surrogate for 1,433 cases. Within 2 years, these persons underwent a complete ocular examination. At that time, an "in-person" self-reported history of eye disease was obtained and disease presence was determined based on ocular photographs. The reporting methods, telephone versus in-person and surrogate versus subject, were compared and the validity of each assessed. Reporting methods were in agreement in better than 90% of all cases. Reporting of cataract showed a sensitivity of 20.4 for surrogate by telephone, 30.2 for self-report by telephone, and 37.8 for self-report at the examination. Sensitivity of reported age-related macular degeneration was poorer, with the highest rate of 17.9 for the "in-person" self-report. Specificity was better than 90.0 for all reporting methods for both cataract and age-related macular degeneration. These data suggest that estimates of prevalence of ocular disease should not be based solely on reported histories, and that clinical determinations are necessary.

Adult↗
PubMed1991

The Beaver Dam Eye Study: visual acuity.

Few current population-based data on visual impairment are available. Visual acuity and impairment were measured in 4926 people between the ages of 43 and 86 years in the defined population participating in the Beaver Dam Eye Study. Visual acuity was measured after refraction, using standardized protocols. Of a possible maximum score of 70 (20/10), the mean number of letters correctly identified (right eye) varied from 55.7 (20/20, n = 1515) in people between the ages of 43 and 54 years to 41.2 (20/40, n = 795) in people 75 years of age or older. Age-specific mean visual acuity scores were consistently and significantly lower in women, who identified three fewer letters on the average than men. Rates of any visual impairment (20/40 or worse in the better eye) or legal blindness (20/200 or worse in the better eye), increased from 0.8% and 0.1%, respectively, in people between the ages of 43 and 54 years to 21.1% and 2.0%, respectively, in people 75 years of age or older. Multivariate analyses showed both sex (women) and age (older) to be significant and independent predictors of poorer visual acuity.

Adult↗
PubMed1991

The Wisconsin Epidemiologic Study of Diabetic Retinopathy. XIII. Relationship of serum cholesterol to retinopathy and hard exudate.

Serum total and high-density lipoprotein (HDL) cholesterol were measured in a sample of individuals examined between 1984 and 1986 for the Wisconsin Epidemiologic Study of Diabetic Retinopathy. There was a significant trend for increasing severity of diabetic retinopathy and of retinal hard exudate with increasing cholesterol in insulin-using persons. Cholesterol levels were not related to the severity of either ocular condition in older-onset patients. High-density lipoprotein-cholesterol was unrelated to the severity of either lesion. In multiple logistic regression analyses, cholesterol was not a significant factor in describing the severity of retinopathy in any group but was a significant factor in describing the severity of retinal hard exudate. Glycosylated hemoglobin and diastolic blood pressure were significant descriptors of the severity of retinopathy in younger-onset patients in these multivariate analyses. Diastolic blood pressure added significantly to explaining the severity of hard exudate in older-onset insulin users. These data support the current management strategies for diabetes, which include control of level of glycemia, blood pressure, and blood lipids.

Adult↗
PubMed1991

The Wisconsin age-related maculopathy grading system.

A new system for grading age-related maculopathy is described and measures of reliability are reported. A number of characteristics of age-related maculopathy are graded in a semiquantitative fashion from stereoscopic 30 degrees color fundus photographs, using a grid to define subfields, standard circles printed on plastic to assess size and area, and a specially designed lightbox to allow better discrimination of subtle drusen. The degree of exact agreement achieved between two trained graders across a variety of lesions ranged from 67.1% for drusen size to 99.6% for geographic atrophy. Kappa scores ranged from 0.55 (for drusen confluence) to 0.95 for geographic atrophy. This system will be useful in epidemiologic studies and clinical trials.

Aging↗
PubMed1991

Cost-effectiveness of strategies for detecting diabetic retinopathy.

A computer model has been developed to determine cost-effectiveness of screening and treatment for diabetic retinopathy from a societal viewpoint. This model was used to evaluate biannual and annual screening programs using ophthalmoscopy, fundus photography with a "nonmydriatic camera," and photography with a "mydriatic camera." Computations were performed for three subpopulations formed by patients with younger onset diabetes (age at diagnosis less than 30 years) of 5 years or more duration, with older onset diabetes (age at diagnosis greater than or equal to 30 years) who are taking insulin, and with older onset diabetes not taking insulin. Population characteristics are from a well-described southern Wisconsin population where data are available, but the computer model may be specialized to other population. Generally costs of screening programs appear to be recovered by avoided costs of blindness in the population subgroups taking insulin; however, the cost of screening programs generally are not recovered by avoiding costs of blindness in the older onset population subgroup not taking insulin. It was estimated that supplying annual examination with mydriatic fundus photography as a screening program to a cohort of 1,000 diabetics from the younger onset population who have been diagnosed at least 5 years and who are currently not receiving care might save 319 sight years over the lifetime of the cohort. This program will save 62 sight years in an older onset cohort who are taking insulin, and 21 sight years in the older onset population not taking insulin (all benefits are presented as present values computed with an annual discount rate of 5%). Other programs achieve slightly lower savings in each subpopulation.

Adult↗
PubMed1991

Cause-specific mortality in a population-based study of diabetes.

BACKGROUND: Mortality from vascular diseases has been reported to be high in diabetic persons. METHODS: To evaluate mortality from these and other specific causes, we examined cause-specific age-sex standardized mortality ratios in a geographically defined population of younger onset (diagnosed before age 30 and taking insulin, n = 1200) and older onset (diagnosed after age 30, n = 1772) diabetic persons followed for 8.5 years. Cause of death was determined from death certificates. RESULTS: In younger onset persons, age-sex standardized mortality ratios were significantly high (P less than .05) for all causes of death (7.5) as well as for diabetes (191), all heart disease (9.1), ischemic heart disease (10.1), other heart disease (6.3), nephritis and nephrosis (41.2), accidents (2.9), and all other causes (3.2). In older onset persons, age-sex standardized mortality ratios were significantly high for all causes of death (2.0) as well as for diabetes (16.8), all heart disease (2.3), ischemic heart disease (2.3), other heart disease (2.1), stroke (2.0), and pneumonia and influenza (1.7). CONCLUSIONS: Diabetic persons experience very high mortality, especially from vascular diseases, compared to the general population.

Adult↗
PubMed1991

Association of elevated IGF-I levels with increased retinopathy in late-onset diabetes.

Insulinlike growth factor I (IGF-I) has been suggested to play a role in the pathogenesis of proliferative diabetic retinopathy (PDR). We determined IGF-I levels in subjects in a large population-based study of 928 people with diabetes diagnosed at 30 yr of age or older. PDR was found in 15.7% of the insulin-using group (n = 517) and in 2.8% of those not using insulin (n = 397). The mean serum level of IGF-I was 208 micrograms/L in individuals using insulin and 222 micrograms/L in those not using insulin, both significantly lower than in a nondiabetic comparison group (278 micrograms/L, P less than 0.0001). Logistic regression analysis was used to examine the relationship between IGF-I and PDR while controlling for other factors associated with the presence of PDR. After controlling for duration of diabetes, glycosylated hemoglobin, systolic blood pressure, presence of proteinuria, and age at diagnosis, higher levels of IGF-I were significantly associated with an increased frequency of PDR (P = 0.025) in the group using insulin. In individuals not using insulin, higher levels of IGF-I were associated with an increased frequency of PDR or moderate non-PDR (P = 0.08). These data suggest that higher IGF-I levels may be a risk factor for the development of severe retinopathy in people with diabetes diagnosed at 30 yr of age or older.

Adult↗
PubMed1991

Factors determining recall of examination results in diabetic population.

OBJECTIVE: To determine factors influencing recall of examination results after 4 yr. RESEARCH DESIGN AND METHODS: At two examinations that were 4 yr apart, a diabetic population was asked, "Have you been told that your diabetes has affected the back of your eyes, that is the retina?" Participants were informed by letter whether they had retinopathy. Subjects in this study included younger-onset (n = 311) and older-onset (n = 279) diabetic subjects who had retinopathy at baseline and did not know it. RESULTS: Forty-two percent of younger-onset and 29% of older-onset subjects recalled at follow-up that they had been told their diabetes had affected their eyes. People in both groups were more likely to recall they had retinopathy if they had more severe retinopathy, had more symptoms of neuropathy and peripheral vascular disease, had seen an ophthalmologist within 2 yr, or monitored their blood glucose more often. In addition, younger-onset diabetic subjects with poorer visual acuity or who were on a combination insulin regimen and older-onset people taking insulin, having more education, or who were younger were more likely to recall they had retinopathy. Factors not associated with recall in either group included sex, duration of diabetes, proteinuria, glycosylated hemoglobin, and family income. CONCLUSIONS: These results underscore the need to develop better methods to deliver health-care information to people who have diabetes.

Adult↗
PubMed1991

Association of cigarette smoking with diabetic retinopathy.

OBJECTIVE: To determine whether cigarette smoking is associated with the incidence and progression of diabetic retinopathy. RESEARCH DESIGN AND METHODS: Younger-onset diabetic subjects who had been diagnosed at less than 30 yr of age and taking insulin (n = 1210) and a random sample of older-onset diabetic subjects diagnosed at greater than or equal to 30 yr of age (n = 1780) were selected. Baseline examinations were conducted on 996 younger- and 1370 older-onset subjects. Incidence of retinopathy was based on 138 younger-onset and 154 older-onset insulin-taking subjects and 321 older-onset non-insulin-taking subjects who were free of retinopathy at baseline. Progression of retinopathy was based on 530 younger-onset and 418 older-onset insulin-taking subjects and 486 older-onset non-insulin-taking subjects with less than proliferative diabetic retinopathy at baseline. RESULTS: Baseline smoking history was categorized by status (nonsmoker, ex-smoker, current smoker) and pack-years smoked while diabetic. Retinopathy was documented by stereoscopic fundus photography. In univariate analyses, the only significant association was between pack-years and progression to proliferative diabetic retinopathy in older-onset insulin-taking subjects (P less than 0.01). After controlling for known risk factors for the incidence and progression of retinopathy, pack-years smoked was borderline significant (P = 0.052) in predicting incidence of retinopathy in younger-onset subjects. Smoking was not associated with incidence in older-onset subjects or with progression or progression to proliferative diabetic retinopathy in any of the groups. CONCLUSIONS: Smoking is not likely to be an important risk factor for diabetic retinopathy.

Adult↗
PubMed1991

The incidence of gross proteinuria in people with insulin-dependent diabetes mellitus.

Epidemiologic data on the incidence of gross proteinuria in people with diabetes are important in medical counseling, in projecting estimates of needs and costs of health care, and for developing approaches to prevent renal complications. We performed a population-based incidence study in southern Wisconsin of insulin-taking diabetic persons diagnosed before 30 years of age. The presence of gross proteinuria (greater than or equal to 0.30 g/L) was determined by means of a reagent strip. The incidence of proteinuria in a 4-year interval was 14.4% (95% confidence interval, 11.7% to 17.0%). The relative risk of developing proteinuria after 4 years for those with glycosylated hemoglobin levels in the highest quartile compared with those in the lowest quartile was 3.0 (95% confidence interval, 1.6 to 5.3). The incidence of proteinuria was also associated with higher diastolic blood pressure, being male, taking more insulin, and having more severe retinopathy at the baseline examination. The relationship between glycosylated hemoglobin level and the incidence of proteinuria was significant even after controlling for these other risk variables. These data suggest that hyperglycemia, as measured by glycosylated hemoglobin level, is a significant risk factor for the development of gross proteinuria.

Adolescent↗
PubMed1990

Assessment of cataracts from photographs in the Beaver Dam Eye Study.

Presence and severity of age-related cataract was determined in adults 43 to 84 years of age in Beaver Dam, Wisconsin. Duplicate photograph gradings for nuclear sclerosis (n = 1160), cortical opacities (n = 1159), and posterior subcapsular cataract (n = 1137) were performed. There are five levels of nuclear sclerosis. Exact agreement occurred in 64.7% of the cases; agreement within one category in 99.8%. For cortical opacities, graders estimate involved area in nine segments of the lens. When the continuous scale is divided into 12 categories of severity, exact agreement varied between 73.5 and 82.4%; for agreement within one category, rates varied between 84.6 and 89.9%. For posterior subcapsular cataracts, exact agreement for involvement of the central circle occurred in 95.0% and agreement within one category occurred in 97.7%. Intraobserver comparisons disclosed similar concordance. These grading schemes are semiquantitative, reproducible, and can be performed for the large numbers of photographs from population-based studies.

Adult↗
PubMed1990

Increased testosterone in type I diabetic subjects with severe retinopathy.

Diabetic retinopathy rarely occurs before puberty, suggesting that changes in sex hormones may influence the development of this condition. The authors measured serum testosterone, estradiol, DHEA-S, and sex hormone binding globulin levels in 26 men and 22 women with type I diabetes from the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR), a population-based study of diabetic complications. The mean age was 23 years and the mean duration of diabetes was 14 years. Subjects with proliferative or preproliferative retinopathy (greater than or equal to retinopathy level 51-80) were matched by duration of diabetes (+/- 2 years) and sex to subjects with minimal or no retinopathy (less than or equal to retinopathy level 21). Seven stereoscopic retinal photographs of each eye were obtained and photographs were read by the University of Wisconsin Reading Center. Serum testosterone concentrations were significantly higher in male diabetic subjects with proliferative retinopathy (648 +/- 36 ng/dl) than in male diabetic subjects with minimal or no retinopathy (512 +/- 43 ng/dl) (P = 0.017). No other statistically significant differences in sex hormones between subjects with and without proliferative retinopathy were observed. Although these results should be regarded as preliminary because of the small number of subjects, they support the hypothesis that testosterone concentrations may be associated with the development of retinopathy in type I diabetic patients.

Adolescent↗
PubMed1990

The validity of estimating the incidence of diabetic retinopathy from prevalence.

A method for estimating incidence rates of a disease from prevalence proportions with differential mortality was validated for diabetic retinopathy in a large population of diabetic persons followed for 4 years, 1980-1982 to 1984-1986, in southern Wisconsin. Four-year age- or duration-specific incidence rates of retinopathy were calculated from prevalence and mortality in persons with and those without retinopathy. These rates were lower than the actual rates obtained at the 4-year follow-up examination by 50% or more in most age intervals in both younger and older onset persons. Estimated duration-specific rates were up to 29 and 57% lower than the actual rates in younger and older onset persons, respectively. These discrepancies could not be accounted for by violations of the assumptions underlying the method. In applying the method to diabetic retinopathy, age- and duration-specific incidence may be more appropriate. Such estimated rates agree well with actual rates except in older onset persons with diabetes of short duration.

Adolescent↗