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Biomedical subjects

E J Boyko

Publications and source records attributed to E J Boyko.

At least 55 records · Page 3Linked to original sources
PubMed1997

Hypertension in Alaska Natives: association with overweight, glucose intolerance, diet and mechanized activity.

OBJECTIVE: Determine the prevalence of hypertension in Alaska Natives and evaluate risk factors. DESIGN: Population-based univariate and multivariate analysis of blood pressure in 1124 Alaska Natives over 20 years of age. RESULTS: The sample had mean: age 45 years, body mass index 27, systolic pressure 123 mmHg and diastolic pressure 73 mmHg. The age-adjusted rate of hypertension > or = 160/95 mmHg was 9.1% and 6.8% among Athabascan Indians and Yup'ik Eskimos, respectively. After controlling for age and sex there was significantly more hypertension among Athabascan Indians (OR = 1.53, CI = 1.07-2.2, p = 0.019) compared to Yup'ik Eskimos. Race was significantly associated with blood pressure > or = 140/90 when controlled for age and overweight (p = 0.01, OR = 0.78, CI = 0.69-0.95). The presence of hypertension was significantly associated with the following: intake of non-indigenous food (p = 0.01); mechanized activities (p = 0.01); and glucose intolerance in both women (p = 0.043) and men (p = 0.001). Multiple regression analysis revealed age (OR = 1.06, CI = 1.05-1.08) and overweight in both men (OR = 3.02, CI = 1.85-4.93) and women (OR = 2.76, CI = 1.81-4.19) to be significantly associated with BP > or = 140/90. CONCLUSION: Hypertension is no longer rare in Alaska Natives and is associated with overweight, non-indigenous diet, mechanized activities, and glucose intolerance.

Adult↗
PubMed1997

Prevalence of radiographic foot abnormalities in patients with diabetes.

Clinicians are increasingly aware that mechanical aspects of foot deformities, such as Charcot changes, clawtoes, bunion deformities, or cavus or planus foot deformities, might have an impact on the occurrence, potential healing, and recurrence of foot ulcers. We report the prevalence of plain radiographic changes and attempt to rate the severity of those deformities in the feet of 456 diabetic veteran medicine clinic enrollees. All 456 radiographs were reviewed by orthopaedic surgeons to specifically identify Charcot changes, presence of arterial calcification, dislocation of the lesser toe metatarsophalangeal joints, hallux interphalangeal joint dislocation, and radiographic evidence of previous surgery. Radiographs of 428 patients were taken while weight-bearing, and these were reviewed to quantify hallux valgus angles, intermetatarsal 1-2 angles, fifth metatarsal-proximal phalangeal angles, second metatarsal lengths, lateral talocalcaneal and talar-first metatarsal angles, and claw toe deformities. The prevalence of Charcot changes was 1.4% (six subjects), and all had radiographic evidence of midfoot Charcot changes. Other deformities, such as clawtoes, hallux valgus, lesser toe joint dislocations, and alterations in arch height, are more common in veterans with diabetes.

Adult↗
PubMed1997

Effect of regional fat distribution and Prader-Willi syndrome on plasma leptin levels.

Variability in the relationship of plasma leptin level to body mass index (BMI) could be caused by imperfect estimation of adipose mass by the BMI, heterogeneity in the pathogenesis of obesity in mixed subject groups, or variation in adipose tissue distribution. To investigate these possibilities, we examined the correlation of plasma leptin and BMI in an ethnically mixed population, a group of subjects with the Prader-Willi syndrome, and a group of Japanese-American subjects who underwent computerized tomographic measurement of adipose tissue cross-sectional areas. Highly significant and indistinguishable linear relationships between plasma leptin levels and BMI were found in the three study groups. Intersubject variability was also similar in the three groups and was reduced only when more accurate techniques for assessing adipose tissue mass were substituted for the BMI. The plasma leptin level of Japanese-American subjects in the highest quartile of intraabdominal fat area (mean area = 154.5 +/- 38.4 cm2) was 12.5 +/- 8.7 ng/mL as compared to 12.3 +/- 9.6 ng/mL (P = 0.91) for subjects in the lowest quartile of intraabdominal fat area (mean area = 51.2 +/- 20.1 cm2, P < 0.001 for difference in fat areas). We conclude that the circulating leptin level reflects total adipose tissue mass rather than a combination of adipose tissue mass and distribution, and that the Prader-Willi syndrome does not alter the relationship between these two variables.

Adipose Tissue↗
PubMed1997

Risk factors for diabetic peripheral sensory neuropathy. Results of the Seattle Prospective Diabetic Foot Study.

OBJECTIVE: To identify risk factors for diabetic lower-extremity peripheral sensory neuropathy prospectively in a cohort of U.S. veterans with diabetes. RESEARCH DESIGN AND METHODS: General medicine clinic outpatients with diabetes were followed prospectively for the development of insensitivity to the 5.07 monofilament on the foot. RESULTS: Of 775 subjects, 388 (50%) had neuropathy at baseline. Of the 387 subjects without neuropathy at baseline, 288 were followed up, and of these, 58 (20%) developed neuropathy. Multivariate logistic regression modeling of prevalent neuropathy controlling for sex and race revealed independent and significant associations with age, duration of diabetes, glycohemoglobin level, height, history of lower-extremity ulceration, callus, and edema; an independent and inverse correlation was noted with ankle-arm index. Risk factors for incident neuropathy in multivariate logistic regression included age, baseline glycohemoglobin level, height, history of ulcer, and CAGE screening instrument alcohol score; current smoking and albumin level were inversely associated with risk. CONCLUSIONS: Poorer glycemic control increases the risk of neuropathy and is amenable to intervention. Height and age directly increase risk of neuropathy and may help identify patients at risk. A proportion of neuropathy in diabetic veterans is probably due to or worsened by alcohol ingestion. Neuropathy was less common in current smokers than subjects not currently smoking.

Age Factors↗
PubMed1997

Evidence that plasma leptin and insulin levels are associated with body adiposity via different mechanisms.

OBJECTIVE: Like insulin, the adipocyte hormone, leptin, circulates at levels proportionate to body adiposity. Because insulin may regulate leptin secretion, we sought to determine if plasma leptin levels are coupled to body adiposity via changes in circulating insulin levels or insulin sensitivity and whether leptin secretion from adipocytes is impaired in subjects with NIDDM. RESEARCH DESIGN AND METHODS: We used multiple linear regression to analyze relationships between BMI (a measure of body adiposity) and fasting plasma levels of leptin and insulin in 98 nondiabetic human subjects (68 men/30 women) and 38 subjects with NIDDM (27 men/11 women). The insulin sensitivity index (Si) was also determined in a subset of nondiabetic subjects (n = 38). RESULTS: Fasting plasma leptin concentrations were correlated to both BMI (r = 0.66, P = 0.0001) and fasting plasma insulin levels (r = 0.65, P = 0.0001) in nondiabetic men and women (r = 0.58, P = 0.0009 for BMI; r = 0.47, P = 0.01 for insulin). While the plasma leptin level was also inversely related to Si (r = -0.35; P = 0.03), this association was dependent on BMI, whereas the association between insulin and Si was not. Conversely, the relationship between plasma leptin and BMI was independent of Si, whereas that between insulin and BMI was dependent on Si. The relationship between plasma leptin levels and BMI did not differ significantly among NIDDM subjects from that observed in nondiabetic subjects. CONCLUSIONS: We conclude that 1) body adiposity, sex, and the fasting insulin level are independently associated with plasma leptin level; 2) because NIDDM does not influence leptin levels, obesity associated with NIDDM is unlikely to result from impaired leptin secretion; and 3) insulin sensitivity contributes to the association between body adiposity and plasma levels of insulin, but not leptin. The mechanisms underlying the association between body adiposity and circulating levels of these two hormones, therefore, appear to be different.

Adult↗
PubMed1996

Association between use of spermicide-coated condoms and Escherichia coli urinary tract infection in young women.

Diaphragm/spermicide use increases the risk of urinary tract infection (UTI). To determine whether spermicide-coated condoms are also associated with an increased risk of UTI, the authors conducted a case-control study at a large health maintenance organization in Seattle, Washington. Cases were sexually active young women with acute UTI caused by Escherichia coli, identified from computerized laboratory files during 1990-1993. Age-matched controls were randomly selected from the enrollment files of the plan. Of 1,904 eligible women, 604 cases and 629 controls (65%) were interviewed. During the previous year, 40% of the cases and 31% of the controls had been exposed to any type of condom. The unadjusted odds ratio for UTI increased with frequency of condom exposure from 0.91 (95% confidence interval (CI) 0.65-1.28) for weekly or less during the previous month to 2.11 (95% CI 1.37-3.26) for more than once weekly. Exposure to spermicide-coated condoms conferred a higher risk of UTI, with odds ratios ranging from 1.09 (95% CI 0.58-2.05) for use weekly or less to 3.05 (95% CI 1.47-6.35) for use more than once weekly. In multivariate analyses, intercourse frequency (odds ratio (OR) = 1.14 per weekly episode), history of UTI (OR = 2.64), and frequency of spermicide-coated condom exposure (OR = 3.34 for more than once weekly and 5.65 for use more than twice weekly) were independent predictors of UTI. Spermicide-coated condoms were responsible for 42% of the UTIs among women who were exposed to these products.

Adolescent↗
PubMed1996

Predictors of transcutaneous oxygen tension in the lower limbs of diabetic subjects.

We examined neuropathy, ankle pressure index (API), and other factors as predictors of transcutaneous oxygen (TcPO2) in the lower limbs of 657 diabetic subjects. Eligible subjects underwent a clinical assessment that included three standard measures of autonomic neuropathy. TcPO2 measurements were performed at 37 degrees C and 44 degrees C at four lower limb locations. Associations between potential predictors and TcPO2 were tested using univariate and multivariate statistics. Mean TcPO2 at any site did not differ by presence of autonomic neuropathy at either temperature, except for a significantly lower value at 44 degrees C below the knee (56.5 versus 59.2 mmHg, p = 0.021). In multivariate analysis, autonomic neuropathy was significantly and independently related to leg 44 degrees C TcPO2 only (coefficient = -2.6734, p = 0.0182). Much stronger associations were seen between TcPO2 and age, ankle blood pressure, and relative body weight on the plantar foot; and between API, glycosylated haemoglobin, ankle blood pressure, and pedal oedema on the dorsal foot and leg. We conclude that factors related to lower limb TcPO2 vary depending on measurement site. Autonomic neuropathy is not an important determinant of TcPO2 in the feet of diabetic subjects. Although several predictors of TcPO2 were identified, most of the variance of this measurement remains unexplained.

Algorithms↗
PubMed1996

The negative association between traditional physical activities and the prevalence of glucose intolerance in Alaska Natives.

The once low prevalence of non-insulin-dependent (Type 2) diabetes (NIDDM) in Eskimos and Indians has risen approximately fourfold over the past 30 years, suggesting the presence of a non-genetic factor affecting NIDDM prevalence. At the same time, traditional physical activities required of a subsistence (self-sufficiency) lifestyle have diminished. Since physical activity has been shown to prevent NIDDM in other populations, we performed a case-control study of physical activity and glucose intolerance in 666 Yup'ik Eskimos and Athabaskan Indians > or = 40 years old in 15 villages in the Yukon Kuskokwim Delta in Alaska. Self-administered questionnaires were used to determine whether subjects participated in a number of traditional activities and/or their modern counterpart (for example, dog sledding and riding motorized vehicles). Intensity values and a score were defined for the activities. Cases included known or newly discovered impaired glucose tolerance or NIDDM. Newly discovered cases were defined by oral glucose tolerance testing of those individuals were screening blood glucose values > or = 6.7 mmol l-1 by random capillary blood glucose testing. Cases included 11 newly discovered (1 with a history of IGT) and 26 known cases of NIDDM, and 17 newly discovered and 1 known cases of IGT. The results showed that, compared to a reference group with low-level physical activity, moderate level physical activity (odds ratio, OR, 0.7, 95% confidence interval [CI] 0.4-1.3) and high level activity (OR 0.2, CI 0.1-0.6) were associated with a lower prevalence of glucose intolerance, adjusted for age, ethnicity, body mass index, and sex.

Age Distribution↗
PubMed1996

Increased mortality associated with diabetic foot ulcer.

The objective of this study was to evaluate the relationship between foot ulceration and short-term mortality in veterans of the American military services with diabetes mellitus. A total of 725 diabetic subjects participated in a prospective study of risk factors for lower extremity complications between 1990 and 1994. Mean follow-up was 691.8 days (+/-SD 339.9, range 28-1436 days). Subjects who died during follow-up (n = 72) had a similar mean duration of diabetes to those who survived (12.6 years vs 11.2), but their mean age was greater (65.9 years vs 63.2, p = 0.026). The relative risk (RR) of death was 2.39 (95% confidence interval (CI) 1.13 to 4.58) in the subjects who developed foot ulcer (n = 88) compared to those who did not. The risk of death for those with foot ulcer was 12.1 per 100 person-years of follow-up compared to 5.1 in those without foot ulcer. Cox regression analysis demonstrated a greater than two-fold increased risk of death in ulcerated subjects after adjustment for age; diabetes type, duration, and treatment; glycosylated hemoglobin level; history of lower extremity amputation; and cumulative pack years smoked. Higher ankle-arm index was significantly related to lower mortality risk, independent of foot ulcer occurrence. We conclude that foot ulcer and lower extremity vascular disease are related to a higher risk of death in diabetic subjects. The reasons for this excess mortality require further investigation.

Age Factors↗
PubMed1996

Cerebrospinal fluid leptin levels: relationship to plasma levels and to adiposity in humans.

The adipocyte hormone, leptin (OB protein), is proposed to be an "adiposity signal" that acts in the brain to lower food intake and adiposity. As plasma leptin levels are elevated in most overweight individuals, obesity may be associated with leptin resistance. To investigate the mechanisms underlying brain leptin uptake and to determine whether reduced uptake may contribute to leptin resistance, we measured immunoreactive leptin levels in plasma and cerebrospinal fluid (CSF) of 53 human subjects. Leptin concentrations in CSF were strongly correlated to the plasma level in a nonlinear manner (r = 0.92; p = 0.0001). Like levels in plasma, CSF leptin levels were correlated to body mass index (r = 0.43; p = 0.001), demonstrating that plasma leptin enters human cerebrospinal fluid in proportion to body adiposity. However, the efficiency of this uptake (measured as the CSF:plasma leptin ratio) was lower among those in the highest as compared with the lowest plasma leptin quintile (5.4-fold difference). We hypothesize that a saturable mechanism mediates CSF leptin transport, and that reduced efficiency of brain leptin delivery among obese individuals with high plasma leptin levels results in apparent leptin resistance.

Adult↗
PubMed1996

Coronary heart disease and NIDDM in Japanese-Americans.

Glucose intolerance is associated with increased risk of coronary heart disease (CHD) in Japanese-Americans, especially in men. Intra-abdominal fat, assessed by computed tomography, is increased in those with both NIDDM and CHD. Increased intra-abdominal fat (visceral adiposity) with CHD is independent of NIDDM or impaired glucose tolerance. The association between NIDDM and CHD may be explained by the association of each of these conditions with visceral adiposity. However, hyperinsulinemia is associated with CHD only in the presence of diabetes, whereas triglyceride levels are elevated with CHD independent of glucose tolerance category. These findings suggest that factors other than insulin levels, such as lipids, may mediate the relationship between visceral adiposity and CHD. Moreover, these relationships are influenced by gender.

Abdomen↗
PubMed1996

Low insulin secretion and high fasting insulin and C-peptide levels predict increased visceral adiposity. 5-year follow-up among initially nondiabetic Japanese-American men.

Insulin resistance and hyperinsulinemia occur more frequently in subjects with greater visceral adiposity, but it is not known whether these metabolic abnormalities precede or follow visceral fat accumulation. We prospectively studied the development of visceral adiposity in relation to fasting and stimulated insulin and C-peptide levels. We followed 137 nondiabetic, second-generation Japanese-American men for changes in visceral adiposity over 5 years. Intra-abdominal fat (IAF) area (square centimeters) was measured at the umbilicus by computed tomography at baseline and after 5 years. Plasma insulin and C-peptide levels were measured after an overnight fast and during an oral glucose tolerance test. Beta-cell function was measured by the insulin secretion ratio (30-0 min plasma insulin difference)/(30-0 min plasma glucose difference). After adjustment for baseline IAF in multiple linear regression models, baseline fasting insulin (coefficient = 0.241, P = 0.048) and C-peptide (coefficient = 38.538, P < 0.001) levels were positively correlated, while the baseline insulin secretion ratio was negatively correlated with IAF change (coefficient = -0.099, P = 0.027). With IAF difference coded as a dichotomous variable (> 0 cm2 vs. < or = 0 cm2), the highest versus lowest tertile of baseline fasting insulin (odds ratio [OR] = 3.0, 95% CI 1.0-9.7) and fasting C-peptide (OR = 8.1, 95% CI 2.4-26.8) levels and the lowest versus highest tertile of the insulin secretion ratio (OR = 3.3, 95% CI 1.0-10.0) were associated with higher odds of IAF gain. Greater insulin resistance and reduced insulin secretion precede visceral fat accumulation in nondiabetic Japanese-American men.

Abdomen↗
PubMed1996

Visceral adiposity, fasting plasma insulin, and lipid and lipoprotein levels in Japanese Americans.

OBJECTIVE: To examine the associations among visceral and subcutaneous adiposity, body-mass-index (BMI), fasting plasma insulin, lipid, and lipoprotein levels. DESIGN: Cross-sectional observational study. SUBJECTS: Non-diabetic second- (Nisei, n = 290) and third-generation (Sansei, n = 229) Japanese Americans. MEASUREMENTS: Intra-abdominal (IAF) and subcutaneous abdominal fat (SAF) area were measured using computed tomography. Fasting plasma insulin, lipid, and lipoprotein levels were measured using standard methods. RESULTS: Higher fasting insulin was significantly related to greater mean IAF and SAF area, plasma triglycerides, total HDL and HDL2 cholesterol in men and women of both generations. In a multiple linear regression analysis model among Nisei adjusted for gender, age, SAF, antihypertensive medication use, smoking, alcohol use, and exercise energy expenditure, IAF area and fasting insulin level were independently correlated with plasma triglycerides (IAF r = 0.22, fasting insulin r = 0.23), total HDL (IAF r = -0.29, fasting insulin r = -0.28), HDL2 (IAF r = -0.30, fasting insulin r = -0.27), and HDL3 cholesterol (IAF r = -0.19, fasting insulin r = -0.19). Among Sansei, similar associations were seen, except that fasting insulin was unrelated to total HDL or HDL3 cholesterol. These effects differed by gender in several instances. CONCLUSIONS: Both visceral adiposity and fasting insulin level are significantly and independently related to adverse levels of lipids and lipoproteins in both generations of nondiabetic Japanese Americans. The association between adverse lipid profile and visceral obesity is not mediated solely through detrimental effects of intra-abdominal fat deposition on fasting insulin level.

Adipose Tissue↗
PubMed1996

Proinsulin levels predict the development of non-insulin-dependent diabetes mellitus (NIDDM) in Japanese-American men.

Disproportionate hyperproinsulinaemia is a manifestation of the beta-cell dysfunction observed in NIDDM. However, it is unclear when this abnormality develops and whether it predicts the development of the disease. To examine whether changes in proinsulin levels predict the development of NIDDM, baseline measurements of proinsulin and immunoreactive insulin levels were made in 87 second-generation Japanese-American men, a population at high risk for the subsequent development of NIDDM. Subjects were categorized at baseline using WHO criteria as having normal glucose tolerance (NGT; n = 49) or impaired glucose tolerance (IGT; n = 38). After a 5-year follow-up period, subjects were recategorized as having NGT, IGT or NIDDM using the same criteria. During follow-up, 16 subjects developed NIDDM while 71 were NGT or IGT. At baseline, individuals who subsequently developed NIDDM were more obese as measured by intra-abdominal fat area on computed tomography (p = 0.046), had higher fasting glucose (p = 0.0042), 2-h glucose (p = 0.0002), fasting C-peptide (p = 0.0011), fasting proinsulin levels (p = 0.0033), and had disproportionate hyperproinsulinaemia (p = 0.056) when compared to those who remained NGT or IGT after 5 years of follow-up. These findings suggest that alterations in proinsulin levels may also predict the subsequent development of NIDDM.

Asian↗
PubMed1996

Hypertension in Japanese Americans: the Seattle Japanese-American Community Diabetes Study.

AMONG SEATTLE'S JAPANESE AMERICANS, hypertension is associated with older age, male gender (in the younger age groups), glucose intolerance (impaired glucose tolerance and diabetes), and visceral obesity (measured by computed tomography). The gender difference in prevalence of hypertension is absent in those ages 65 to 74 and in those with diabetes. In the absence of diabetes, hypertension is not associated with fasting plasma insulin levels in the older second generation, but it is in the younger third generation. The association of hypertension with plasma insulin in the third generation may be due to the association between diabetes and plasma insulin and the presence of many prediabetic individuals in this generation. About three-fourths of Japanese Americans are aware of their hypertension, slightly more than half of hypertensive Japanese Americans are being treated with anti-hypertensive medication, and of those receiving anti-hypertensive medication, less than half have their hypertension controlled. Women tend to be less aware of hypertension, to receive anti-hypertensive medication less often, and to have their hypertension less well-controlled than men.

Adult↗
PubMed1995

Susceptibility to development of central adiposity among populations.

There is good evidence that central (visceral) adiposity is important in the development of the insulin resistance or metabolic syndrome (obesity, hyperinsulinemia, dyslipidemia, glucose intolerance, hypertension, and coronary heart disease). It is proposed that some non-Caucasian populations are especially susceptible to development of this syndrome, and that lifestyle changes may play important etiologic roles. We postulate that this is due to the presence in these populations of a genetic predisposition to weight gain, perhaps related to a "thrifty" genotype, leading to the concentration of weight gain in visceral fat depots, when there is exposure to conditions associated with westernization.

Adipose Tissue↗
PubMed1995

Community patterns of transdermal nicotine use and provider counseling.

OBJECTIVES: To examine how transdermal nicotine is prescribed and used in the general population, and to identify variables associated with successful smoking cessation in patch users. DESIGN: Retrospective cohort survey. SETTING: A random sample of 70 pharmacies in King County, Washington, were asked to participate. Of those, 33 pharmacies ran computer searches of prescriptions for any nicotine patch dispensed between July 1 and December 31, 1992. A total of 1,087 individuals receiving patches were identified. PATIENTS: At least eight months after the nicotine patches were purchased, 972 subjects received questionnaires by mail from the participating pharmacies. The survey was completed by 433 (45.2%) subjects. MAIN RESULTS: Eighty percent of the respondents requested patches from a provider, 81% of whom were primary care physicians. Ninety-six percent used the patch, 45% smoked while using the patch, and 37% reported having quit smoking. Smoking cessation was associated with daily patch application (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.2), abstinence during patch use (OR 7.7, 95% CI 4.8-12.5), and a longer duration of patch use (p = 0.001). A score reflecting counseling intensity by the provider was associated with abstinence while using patches and smoking cessation (chi 2 for tread = 0.01 and 0.04, respectively). CONCLUSIONS: Most nicotine patch users request treatment from a primary care physician, suggesting motivation to quit. Almost half continue to smoke while using the patch, a behavior that appears related to a lower level of counseling and an inability to quit. Increasing counseling may positively impact nicotine-patch-assisted smoking cessation in the general population.

Administration, Cutaneous↗