Biomedical subjects

H Kushner

Publications and source records attributed to H Kushner.

At least 37 records · Page 2Linked to original sources

PubMed1998

Can cardiovascular risk be predicted by newborn, childhood, and adolescent body size? An examination of longitudinal data in urban African Americans.

OBJECTIVE: Recent retrospective studies of older adults have demonstrated a correlation between lower birth weight and hypertension and insulin resistance. We tested this finding in our sample of urban African Americans with prospective data on growth and blood pressure and also tested other variables (in addition to birth weight) for their relationship to adult cardiovascular risk. STUDY DESIGN: A prospective study of birth weight, growth, and blood pressure (Philadelphia Perinatal Collaborative Project) followed a sample of 137 African Americans, with nine examinations from birth through 28.0 +/- 2.7 years. Metabolic measurements (oral glucose tolerance testing, euglycemic hyperinsulinemic clamp, and plasma lipid concentration) were performed on the subjects as adults. Bivariate correlations among parameters were computed using the Pearson r. The chi-squared statistic was used to determine associations of outcomes with birth weight. Stepwise multiple linear regressions were computed using newborn, early childhood, adolescent, and young adult parameters to predict adult outcomes. RESULTS: Birth weight and blood pressure at age 28 years are not correlated (Pearson r = 0.06). Birth weight is also unrelated to adult obesity. However, weight at 0.3 years and after and body mass index at 7 years and after are correlated with adult weight. Furthermore, weight at age 14 years is significantly negatively correlated with measures of insulin-stimulated glucose use, indicating that obese adolescents may be at greater risk than nonobese adolescents for development of non-insulin dependent diabetes in adulthood. CONCLUSIONS: We found no relationship between birth weight and adult outcomes pertaining to cardiovascular risk in this sample of adult African Americans. However, we did find evidence that somatic growth (body weight and body mass index) is significantly related to obesity and attenuated insulin-stimulated glucose utilization in adulthood. These findings indicate that the origins of adult cardiovascular disease are related to somatic growth, but not intrauterine growth, and are evident during childhood.

Adolescent↗

PubMed1998

Sex hormone-binding globulin and insulin resistance in African-American women.

Sex hormone-binding globulin (SHBG) binds testosterone, determining the level of free, biologically active hormone, and is a sensitive indicator of androgen status in women. SHBG is strongly correlated with high-density lipoprotein (HDL), central obesity, and insulin sensitivity in Caucasian and Mexican-American women, thereby acting as a biologic marker for cardiovascular disease risk. The purpose of this study was to determine if SHBG was a significant correlate of metabolic cardiovascular risk factors in African-American women. Eighty-one nondiabetic, normotensive African-American women were enrolled (mean age, 30 years). After excluding women on oral contraceptives (n = 19), 62 women were examined during the follicular phase of the menstrual cycle. All subjects underwent an oral glucose tolerance test (OGTT) and a euglycemic-hyperinsulinemic insulin clamp, and the lipid and sex hormone levels were measured. Correlation analyses showed a significant correlation between SHBG and the following variables in women: central obesity, body mass index (BMI), HDL cholesterol, apolipoprotein B (apoB), insulin sensitivity adjusted for lean mass (M'), and the sum of insulin during the OGTT. The strongest correlates of SHBG in women were measures of insulin resistance (r = .421, P < .001). SHBG appears to be a biologic marker for insulin resistance, which is linked to cardiovascular risk, in African-American women.

Adult↗

PubMed1998

Evidence for a Turner syndrome locus or loci at Xp11.2-p22.1.

Turner syndrome is the complex human phenotype associated with complete or partial monosomy X. Principle features of Turner syndrome include short stature, ovarian failure, and a variety of other anatomic and physiological abnormalities, such as webbed neck, lymphedema, cardiovascular and renal anomalies, hypertension, and autoimmune thyroid disease. We studied 28 apparently nonmosaic subjects with partial deletions of Xp, in order to map loci responsible for various components of the Turner syndrome phenotype. Subjects were carefully evaluated for the presence or absence of Turner syndrome features, and their deletions were mapped by FISH with a panel of Xp markers. Using a statistical method to examine genotype/phenotype correlations, we mapped one or more Turner syndrome traits to a critical region in Xp11.2-p22.1. These traits included short stature, ovarian failure, high-arched palate, and autoimmune thyroid disease. The results are useful for genetic counseling of individuals with partial monosomy X. Study of additional subjects should refine the localization of Turner syndrome loci and provide a rational basis for exploration of candidate genes.

Adolescent↗

PubMed1998

Iron deficiency anemia due to a Brunner's gland hamartoma.

Brunner's gland hamartomas are rare benign duodenal tumors often discovered incidentally during endoscopy or on an upper gastrointestinal series. These tumors arise mainly in the duodenal bulb and can present with gastrointestinal bleeding or symptoms of intestinal obstruction. When symptomatic, surgical or endoscopic removal can be safely performed and the prognosis is very good. We describe a 63-year-old man presenting with iron deficiency anemia due to a large Brunner's gland hamartoma and review the endoscopic, radiologic, surgical, and pathologic findings.

Anemia, Iron-Deficiency↗

PubMed1998

Birth weight versus childhood growth as determinants of adult blood pressure.

In older white American adults, recent retrospective studies have demonstrated a relationship between lower birth weight and hypertension. Black Americans have a higher occurrence of both lower birth weight and hypertension than do white Americans. To test the low birth weight-high blood pressure hypothesis, data from a prospective study (Perinatal Collaborative Project) were examined. The study followed a sample of 137 black Americans, with nine examinations. Data on birth weight, growth, and blood pressure from birth through 28.0+/-2.7 years were obtained longitudinally. Bivariate correlations among parameters were computed with the Pearson r. Birth weight and blood pressure at age 28 years are not correlated (Pearson r=.06). However, systolic blood pressures measured at 0.3 years and thereafter are correlated with adult systolic blood pressure. Also, weight at 0.3 years and body mass index at 7 years and thereafter are correlated with adult weight. Our data did not confirm the birth weight-blood pressure hypothesis. Rather, we detected significant correlations between preadult measurements of blood pressure and weight with adult measurements. These results indicate that in black Americans, childhood growth is a stronger determinant than intrauterine growth of adult blood pressure.

Adult↗

PubMed1998

Effects of estrogen on nonverbal processing speed and motor function in girls with Turner's syndrome.

The Turner syndrome (TS) phenotype is characterized by a specific neurocognitive profile of normal verbal skills, impaired visual-spatial and/or visual-perceptual abilities, and difficulty with motor function. In the current study, we investigated motor function and nonverbal processing speed in estrogen- and placebo-treated girls (aged 10-12 years) with TS and in age-matched female controls. The goal of this study was to examine whether estrogen replacement therapy would reverse deficits in motor function and in nonverbal processing speed, a measure of the time required to perform certain disparate nonverbal tasks, in adolescent girls with TS. Children received either estrogen (ethinyl estradiol, 12.5-50 ng/kg.day), or placebo for durations of 1-7 yr (mean, 4.0 +/- 2.1 yr) in this randomized, double blind study. Cognitive and motor tasks administered included the Wechsler Intelligence Scale for Children-Revised; nonspatial, repetitive motor tasks (tapping and three tasks from the Paness); and spatially mediated motor tasks [nongrooved pegboard (Lafayette), pursuit rotor, visual-motor integration, and money street map]. Questionnaires administered included the Self-Concept Scale. The major result of this study was the positive estrogen treatment effect on nonverbal processing speed and speeded motor performance in 12-yr-old TS girls. That motor performance would be slower in estrogen-deficient TS females is consistent with previous studies of the influence of estrogen on motor function. Estrogen replacement is thus the most likely explanation for the improved motor speed and nonverbal processing time in the estrogen-treated TS girls compared to that in the placebo-treated TS girls. Whether these findings will influence the psychoeducational outcome or quality of life of females with TS is not yet known.

Child↗

PubMed1997

Discriminant analysis of the Ullrich-Turner syndrome neurocognitive profile.

Ullrich-Turner syndrome (UTS), or monosomy X, is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal IQ) and impaired visual-spatial and/or visual-perceptual abilities. The most frequently described profile in UTS includes difficulty with tasks involving memory and attention, decreased arithmetic skills, and impaired visual spatial processing. We used discriminant function analysis (DFA) to distinguish between the neurocognitive profiles of girls with UTS vs. controls matched for age, height, IQ, and socioeconomic status. DFA is a statistical method for deriving a linear function that optimally weights parameters to permit sensitive and specific differentiation among groups. We developed a modified discriminant function, based on seven cognitive test scores, that successfully discriminated between the UTS and control subjects with a sensitivity of 0.45 and a specificity of 0.97. To validate its performance, we applied the discriminant function to a small group of 45,X UTS subjects (n = 13) and control female subjects (n = 25), ages 7-16 years, who were not part of the previous analyses. The discriminant function (DF) identified 54% of these 13 UTS subjects as having the "UTS neurocognitive profile" and 92% of the 25 control subjects as not having the profile. We also compared the DF scores of UTS girls with various mosaic karyotypes and found that the group with 46,XX mosaicism had significantly higher scores (i.e., closer to normal controls) than the other two mosaic groups (t = 2.86, P < 0.005). The results of this study should be useful for genetic counseling and planning educational programs for girls with UTS.

Adolescent↗

PubMed1997

The relationship in African-Americans of sex differences in insulin-mediated suppression of nonesterified fatty acids to sex differences in fasting triglyceride levels.

Insulin is a potent antilipolytic hormone that promotes the deposition of fat and decreases the release of nonesterified fatty acids (NEFA) from adipose tissue. The purpose of this study was to investigate in African-Americans (AAs) sex differences in insulin-mediated suppression of plasma NEFA and fasting triglyceride (TG) levels. Ninety AAs, 44 men and 46 women with a mean age of 34 +/- 8 years were classified by body mass index (BMI) into three groups: non-obese (22 men and 18 women), obese (12 men and 10 women), and severely obese (10 men and 18 women). In each BMI group, women versus men had greater percent body fat (non-obese, 30 +/- 6 v 18 +/- 6, P < .001; obese, 36 +/- 3 v 26 +/- 2, P < .001; and severely obese, 39 +/- 4 v 29 +/- 4, P < .001). An oral glucose tolerance test (OGTT) was performed with fasting TG levels and plasma insulin and NEFA concentrations obtained at 0, 30, 60, and 120 minutes. In women, insulin-mediated NEFA suppression was similar in each of the three BMI groups (non-obese, 85% +/- 14%; obese, 88% +/- 11%; and severely obese, 87% +/- 10%; P = .8). In men, the percent suppression of NEFA declined with increasing obesity (non-obese, 83% +/- 14%; obese, 71% +/- 21%; and severely obese, 68% +/- 16%; P = .04). Changes in NEFA suppression were reflected in the fasting TG levels. TG levels in women were similar in each BMI group (non-obese, 71 +/- 39 mg/dL; obese; 69 +/- 21; severely obese, 79 +/- 30; P = .7). In contrast, fasting TG levels for men were higher in the higher BMI groups. Plasma TG levels in men were 87 +/- 41 mg/dL for obese, 113 +/- 65 for obese, and 169 +/- 81 for severely obese (P = .001). These data demonstrate sex differences in insulin-mediated NEFA metabolism. In AA women, the maintenance of sensitivity to insulin-mediated suppression of NEFA regardless of the degree of obesity may contribute to the normal plasma TG levels. For AA men, the resistance to insulin-mediated suppression of NEFA in the higher BMI categories may allow more NEFA to be released from adipose tissue into the circulation and available to the liver for synthesis into TG-containing lipoproteins.

Adult↗

PubMed1997

Sodium-lithium countertransport is associated with insulin resistance and urinary albumin excretion in young African-Americans.

Increased activity of the sodium transporter, sodium-lithium countertransport (SLC), is reported in hypertensive white patients with evidence of cardiac and renal injury. The purpose of this study was to determine whether increased SLC activity detects risk for nephropathy or vascular disease in nondiabetic, young adult African-Americans. We examined 85 African-Americans aged 25 to 33 years with measurement of blood pressure, an oral glucose tolerance test to measure insulin response to glucose challenge, and an insulin clamp for insulin sensitivity (M). Fasting plasma lipids were measured, and the Vmax and Km for Na+ were assayed on red blood cells. Urinary albumin excretion (UAE) was measured on timed collections. There was a statistically significant correlation of the Vmax for SLC with M (r = -0.26, P = 0.02) and with UAE (r = 0.25, P = 0.02). The Km for Na+ to activate SLC was also elevated in the subgroup of subjects with elevated Vmax of SLC. There was no significant correlation of SLC with blood pressure in bivariate analysis. Step-wise multiple linear regression analysis of all variables on the Vmax SLC demonstrated that plasma triglyceride, UAE, body mass index, systolic blood pressure, M, and fasting insulin were step-wise selected into the linear regression model (F-ratio = 3.2, df = 77, R = 0.46, P < 0.009). In this young adult African-American population, elevated SLC activity is detected in association with metabolic and lipid alterations typical of insulin resistance. Elevated SLC activity is also associated with higher rates of UAE, suggesting possible evidence of early renal injury.

Adult↗

PubMed1997

Absence of growth hormone effects on cognitive function in girls with Turner syndrome.

Turner syndrome (TS) is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal IQ) and impaired visual-spatial and/or visual-perceptual abilities. We have followed a large sample of girls with Turner syndrome who were enrolled in a long-term, double-blind, placebo-controlled trial of the effects of growth hormone (GH) treatment on final adult height. This study provides a unique opportunity to prospectively evaluate the effects of GH treatment on neurocognitive function in this population of girls with Turner syndrome. The GH- and placebo-treated Turner syndrome subjects were well matched for age, treatment duration, race, karyotype, and socioeconomic status. Treatment (GH or placebo) durations ranged from 1-7 yr. Whether GH deficiency and/or treatment in childhood and adolescence influences cognitive outcome in short children or GH-children is controversial. The major result of this study was the absence of GH treatment effects on cognitive function in girls with Turner syndrome. Our findings are in agreement with most of the previous studies that found no apparent growth hormone treatment effects on cognitive function in growth-hormone deficient children. We conclude that this study does not support a role for growth hormone in influencing childhood brain development in girls with Turner syndrome. Their characteristic nonverbal neurocognitive deficits were not altered with GH treatment into early adolescence.

Child↗

PubMed1996

Gender differences in insulin-induced free fatty acid suppression: studies in an African American population.

This study of African Americans (AA) was designed to investigate gender differences in insulin-induced free fatty acid (FFA) suppression. Sixty AA (34 women, mean age 34 +/- 7.6 years, and 26 men, mean age 30 +/- 2.9 years) participated. All subjects had an oral glucose tolerance test (OGTT). Nineteen women and 18 men also underwent a euglycemic hyperinsulinemic clamp (IC) study. Plasma insulin and FFA concentrations were obtained during both tests at 0, 60, and 120 min. While there was no gender difference in body mass index (P = 0.21), women had greater percent body fat (P < 0.001) calculated by the Siri formula. There was no gender difference in fasting FFA levels, but during the OGTT, women compared to men had significantly greater FFA suppression. Both nonobese and obese women suppressed FFA concentration by 88%, and nonobese and obese men suppressed FFA concentration by 80 and 66% respectively. This gender difference in FFA suppression was significant (P = 0.001) and independent of obesity and insulin concentration. During the IC studies, there were no gender or obesity differences in FFA suppression, with women and men suppressing FFA levels by 87-89% (P = 0.7). Fasting insulin concentrations were higher in obese vs. nonobese (P = 0.03), but fasting FFA concentrations were not different (P = 0.15). For nonobese and obese females, fasting FFA levels were 0.55 +/- 0.24 and 0.44 +/- 0.26 mEq/L, respectively, and for nonobese and obese males, 0.45 +/- 0.2 and 0.35 +/- 0.18 mEq/L, respectively. In women, development of obesity may be enhanced by greater sensitivity to insulin-induced FFA suppression as measured during an OGTT. To detect gender differences in FFA metabolism, the OGTT is superior to the IC. The lack of elevation in fasting FFA levels in obese AA women and men has not been reported in other racial groups and may indicate a greater adipocyte sensitivity to insulin in AA.

Adipocytes↗

PubMed1996

Developmental changes in motor function in girls with Turner syndrome.

The Turner syndrome phenotype is characterized by a particular neurocognitive profile of normal verbal skills, impaired visuospatial and/or visuoperceptual abilities, and difficulty with motor function. We investigated motor function in non-estrogen-treated girls (ages 7-9 and 10-12 years) with Turner syndrome and age-matched female controls. Our goal was to delineate the differences in motor performance between girls with Turner syndrome (n = 78) and control girls (n = 145). Cognitive and motor tasks were administered, as well as nonspatial, repetitive motor tasks, and spatially mediated motor tasks. Questionnaires were also administered. Turner subjects performed less well than the controls on the motor tasks with the greatest spatial demands, particularly in the older age group (age 10-12.9 years). The older control group, unlike the older Turner syndrome group, had significantly increased speed on most of the motor tasks, suggesting a Turner syndrome-associated deficiency in motoric development. The superior performance of the dominant (right) versus the nondominant (left) hand was similar for the Turner syndrome and control groups. In general, the girls with Turner syndrome had evidence of a decreased sense of athletic ability and physical self-image. A likely explanation for motoric deficiency in the older Turner syndrome group relates to their gonadal dysgenesis and estrogen deficiency. In addition to the obvious physical benefits of estrogen replacement, estrogen treatment may have a positive impact on motor function; this will be the subject of future investigations.

Child↗

PubMed1996

Self-concept and behavior in adolescent girls with Turner syndrome: potential estrogen effects.

Data on self-concept and behavior were gathered from 31 girls with Turner syndrome (TS) followed longitudinally between the ages of 12 and 16 and from 89 normal control girls recruited from public schools and assessed cross-sectionally. The two groups of girls were similar in age and racial composition. The girls with TS were treated with estrogen replacement therapy in increasing doses between the ages of 12 and 16 (100-400 ng/kg-day ethinyl estradiol). Their self-reported self-esteem and psychological well-being (Piers-Harris Self-Concept Scale) revealed significant improvement over time for most scales as well as the total score (P < 0.001). Parents reported improvement in problem behaviors, as reflected in the Child Behavior Checklist (CBCL) scales: Behavior Total, Externalizing Behavior, Aggressive Behavior, and Social Problems Behavior scales (all P < 0.001). Analysis of covariance comparing normal controls to the TS subjects revealed that at age 12 yr, TS and normal subjects differed significantly for the School Social Competency sub-scale and the Social Problems Behavior subscale (all P < 0.001). Girls with TS resembled the normal controls on all CBCL scales by ages 14-15 yr. Thus, we found improved self-concept both by self- and parental report in estrogen-treated girls with TS followed longitudinally through adolescence. An analogous correlation with age was not seen in the cross-sectional normal control sample. These findings support positive effects of estrogen on psychological well-being in girls with TS and underscores the need to initiate estrogen replacement therapy by ages 12-14 yr in this population.

Adolescent↗

PubMed1995

Ullrich-Turner syndrome: neurodevelopmental changes from childhood through adolescence.

Our objective was to investigate whether the previously-described neurocognitive pattern in girls with Ullrich-Turner syndrome is found in childhood and adolescence; we used a prospective, controlled study of neurocognitive development in girls with Ullrich-Turner syndrome. The patients included 56 girls with Ullrich-Turner syndrome, and 100 normal age- and verbal IQ-matched female control subjects, whose ages ranged from 6-14 years. All girls with Ullrich-Turner syndrome and the normal control girls received a battery of neurocognitive tests designed to evaluate the following domains: general cognition, memory, academic achievement, language, visual-spatial/perceptual skills, visual-motor skills, attention, and affect recognition. Our results demonstrated consistent findings in Ullrich-Turner syndrome girls across the age range studied. In general, the Ullrich-Turner girls resembled control subjects in terms of verbal and language abilities. We found relatively depressed performance IQ and a significant verbal IQ-performance IQ difference. Significant differences were observed on examination of nonverbal abilities. The Ullrich-Turner girls performed more poorly than control girls on 1) tests of visual-motor skills including the Beery Test of Visual-Motor Integration, the Perceptual Organization Factor, and the Rey-Osterrieth Figures; 2) tests of visual-spatial skills, including the Motor-Free Visual Perception Test; 3) tests of attention, including the Freedom From Distractibility Factor; and 4) the Affective Prosody Affect Recognition Test. Ullrich-Turner subjects showed evidence of multifocal or diffuse right cerebral dysfunction and deficits generally involving nonverbal skills that may be due to X chromosome monosomy, gonadal dysgenesis, or both. Future studies will examine the role of estrogen replacement on cognitive function in Ullrich-Turner syndrome individuals.

Adolescent↗

PubMed1995

Prospective evaluation of a model of risk for HIV infection among injecting drug users.

Data on 3016 out-of-treatment injecting drug users (IDUs) were analyzed in order to replicate findings from an earlier study on risk factors for HIV infection (Iguchi et al., 1992) and evaluate a model for estimating probability of infection. Logistic regression analyses yielded a set of risk factors highly consistent with previous findings. A logistic function was used to estimate subjects' probabilities of infection, and these estimates were strongly correlated with actual HIV prevalence in both the original and current samples. The current study represents a successful replication of earlier findings and supports the validity of the risk model.

Adult↗

PubMed1995

Lipid abnormalities in Turner syndrome.

Turner syndrome is associated with insulin resistance, increased incidence of type II diabetes, and hypertension, all of which are cardiovascular risk factors. The purpose of this study was to evaluate the lipid profile of girls with untreated Turner syndrome, (aged 5 to 14 years; 68% 45,XO) and age-matched, normal girls. A total of 137 girls with Turner syndrome and 70 normal girls had lipid profile measurements, including cholesterol, high-density lipoprotein cholesterol, and triglycerides. Older girls with Turner syndrome (> 11.0 years) had increased cholesterol levels (p < 0.01), compared with control values (190 +/- 38 vs 165 +/- 26 mg/dl). Cholesterol levels were elevated in older subjects with Turner syndrome versus normal subjects, after adjustment for age, karyotype, and body mass index z score effects (p = 0.01). In the subjects with Turner syndrome but not the normal subjects, serum cholesterol values correlated with age, weight, and body mass index z score (p < 0.02). We conclude that adolescent girls with untreated Turner syndrome have significantly increased cholesterol levels, independent of age, body mass index z score, or karyotype, and that these precede any treatment with exogenous estrogen or growth hormone.

Adolescent↗

PubMed1995

Insulin sensitivity, lipids, and blood pressure in young American blacks.

The purpose of this study was to determine whether insulin resistance was linked with alterations in plasma lipids in adult young blacks with borderline hypertension. Ninety-four American blacks participated (46 men, 48 women, age range 28 to 33 years). Within this group of 94 subjects, there were 60 normotensive (Nt) subjects and 36 subjects with borderline hypertension (BHt), defined as blood pressure > 135/85 mm Hg. None of the subjects were diabetic or receiving antihypertension medication. All participants had blood pressure and anthropometric measurements, a fasting lipid profile, an oral glucose tolerance test, and a euglycemic hyper-insulinemic clamp. Insulin-stimulated glucose utilization (M), determined by insulin clamp, was significantly lower in the BHt subjects compared with the Nt subjects (men, Nt 6.91 +/- 0.62 versus BHt 5.54 +/- 0.65; women, Nt 5.97 +/- 0.47 versus BHt 3.79 +/- 0.38 mg.kg-1.min-1, P = .006). When M was corrected for adiposity and expressed in milligrams per kilogram of fat free mass (M'), the difference between Nt and BHt remained significant (P = .006). There was a significant correlation of M' with systolic blood pressure (r = .393, P < .0001), HDL-C (r = .382, P < .0001), triglyceride level (r = 308, P < .001), apolipoprotein A-I (r = .190, P = .033), and apolipoprotein B stepwise multiple linear regression analysis, HDL-C emerged as the most significant lipid component in the model for insulin resistance. These data suggest that in American blacks with mild hypertension, the risk for cardiovascular disease may be augmented in the presence of insulin resistance.

Adult↗

PubMed1995

Albuminuria in association with insulin and sodium-lithium countertransport in young African Americans with borderline hypertension.

The purpose of this study was to determine whether early nephropathy, evidenced by urinary albumin excretion, can be detected in young African American subjects with only borderline hypertension, and whether there is a relationship of albuminuria with insulin resistance and with sodium-lithium countertransport activity. Clinically well young African American men and women including normotensive (blood pressure < 135/85 mm Hg, n = 41) and borderline hypertensive (blood pressure > or = 135/85 mm Hg, n = 26) individuals were studied. Each subject underwent an oral glucose tolerance test and euglycemic hyperinsulinemic clamp study. Albuminuria was measured on timed urine collections. Sodium-lithium countertransport activity was assayed in fresh red blood cells at 280 mmol/L Na+ for full saturation of external Na+ sites. The sum of insulin levels during glucose tolerance was significantly greater in the borderline hypertensive compared with the normotensive subjects (P = .014), and insulin-stimulated glucose utilization during the clamp was significantly lower in borderline hypertensive compared with normotensive subjects (P = .016). Albuminuria was greater in borderline hypertensive compared with normotensive subjects (P = .002). Albuminuria was significantly correlated with fasting plasma insulin concentration (r = .44, P < .002) and the sum of insulins during the glucose tolerance test (r = .45, P < .002). Sodium-lithium countertransport correlated with albuminuria (r = .31, P < .05) as well as significantly with insulin-stimulated glucose utilization during the clamp (r = .44, P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗