Duration of Replication-Competent Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Shedding Among Patients With Severe or Critical Coronavirus Disease 2019 (COVID-19)

BACKGROUND

Patterns of shedding replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in severe or critical COVID-19 are not well characterized. We investigated the duration of replication-competent SARS-CoV-2 shedding in upper and lower airway specimens from patients with severe or critical coronavirus disease 2019 (COVID-19).

METHODS

We enrolled patients with active or recent severe or critical COVID-19 who were admitted to a tertiary care hospital intensive care unit (ICU) or long-term acute care hospital (LTACH) because of COVID-19. Respiratory specimens were collected at predefined intervals and tested for SARS-CoV-2 using viral culture and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Clinical and epidemiologic metadata were reviewed.

RESULTS

We collected 529 respiratory specimens from 78 patients. Replication-competent virus was detected in 4 of 11 (36.3%) immunocompromised patients up to 45 days after symptom onset and in 1 of 67 (1.5%) immunocompetent patients 10 days after symptom onset (P = .001). All culture-positive patients were in the ICU cohort and had persistent or recurrent symptoms of COVID-19. Median time from symptom onset to first specimen collection was 15 days (range, 6-45) for ICU patients and 58.5 days (range, 34-139) for LTACH patients. SARS-CoV-2 RNA was detected in 40 of 50 (80%) ICU patients and 7 of 28 (25%) LTACH patients.

CONCLUSIONS

Immunocompromise and persistent or recurrent symptoms were associated with shedding of replication-competent SARS-CoV-2, supporting the need for improving respiratory symptoms in addition to time as criteria for discontinuation of transmission-based precautions. Our results suggest that the period of potential infectiousness among immunocompetent patients with severe or critical COVID-19 may be similar to that reported for patients with milder disease.

Blood utilization in five Chinese hospitals shows low hemoglobin thresholds in medical patients

BACKGROUND

The number of red blood cell units transfused per capita in China is lower than in western countries and the reason(s) for the difference is unknown.

STUDY DESIGN AND METHODS

We randomly chose 5050 transfused patients from five Chinese hospitals. We compared transfused cases to nontransfused controls matched for the same underlying diagnosis. We assessed the pretransfusion hemoglobin (Hb) trigger and other clinical characteristics associated with transfusion. After stratifying by underlying disease, we compared pretransfusion Hb level in Chinese hospitals to 12 US hospitals.

RESULTS

In 5050 patients who received transfusion, the pretransfusion Hb levels were lower in medical (6.3 g/dL) compared to surgical patients receiving transfusion postoperatively (8.1 g/dL). In patients with nonsurgical diagnoses, the pretransfusion Hb was much lower than that in the United States; the difference in mean Hb level varied by underlying diagnosis from 0.4 to 1.8 g/dL. In case-control analysis of cases (n = 1356) compared to controls (n = 1201), the pretransfusion Hb showed the strongest association with transfusion. Compared to 10 g/dL, the odds ratio (95% confidence interval) for pretransfusion Hb of 7 to 7.9 g/dL was 37.7 (24.8-57.4).

CONCLUSION

Transfusion triggers in five Chinese hospitals appear comparable to those in the United States for surgical patients; however, medical patients have lower pretransfusion Hb levels (approx. 6 g/dL). Of the factors assessed, the pretransfusion Hb was most strongly associated with transfusion. The clinical impact of lower transfusion thresholds used in China is unknown.

Atopic dermatitis complicated by eczema herpeticum is associated with HLA B7 and reduced interferon-γ-producing CD8+ T cells

BACKGROUND

The increased susceptibility of patients with atopic dermatitis (AD) to disseminated viral skin infections such as eczema herpeticum (ADEH+) is poorly understood.

OBJECTIVES

The primary goal of the current study was to determine whether ADEH+ subjects have identifiable defects in cell-mediated immunity that reduce their ability to control viral infections.

MATERIALS AND METHODS

In this study, we evaluated cytokine expression by various subsets of peripheral blood mononuclear cells from ADEH+ (n = 24) compared with AD without a history of viral infections (ADEH-) (n = 20) before and after treatment with herpes simplex virus (HSV).

RESULTS

We found that interferon (IFN)-γ expression after HSV treatment was lower in the CD8+ T cells and monocytes from patients with ADEH+ compared with patients who are ADEH- or nonatopic. Given the induction of CD8+ T cells as the result of antigen presentation by human leucocyte antigen (HLA) class I, consistent with the findings described above we also found that the HLA B7 allele was significantly associated with risk of the ADEH+ phenotype (odds ratio = 1·91, P = 0·02, 125 ADEH+ and 161 ADEH- subjects).

CONCLUSIONS

These data suggest that defects in viral-induced IFN-γ from CD8+ T cells contribute to the ADEH+ phenotype.

Evaluation of vaccine-induced antibody responses: impact of new technologies

Host response to vaccination has historically been evaluated based on a change in antibody titer that compares the post-vaccination titer to the pre-vaccination titer. A four-fold or greater increase in antigen-specific antibody has been interpreted to indicate an increase in antibody production in response to vaccination. New technologies, such as the bead-based assays, provide investigators and clinicians with precise antibody levels (reported as concentration per mL) in ranges below and above those previously available through standard assays such as ELISA. Evaluations of bead assay data to determine host response to vaccination using fold change and absolute change, with a general linear model used to calculate adjusted statistics, present very different pictures of the antibody response when pre-vaccination antibody levels are low. Absolute changes in bead assay values, although not a standard computation, appears to more accurately reflect the host response to vaccination for those individuals with extremely low pre-vaccination antibody levels. Conversely, for these same individuals, fold change may be very high while post-vaccination antibodies do not achieve seroprotective levels. Absolute change provides an alternate method to characterize host response to vaccination, especially when pre-vaccination levels are very low, and may be useful in studies designed to determine associations between host genotypes and response to vaccination.

Increased risk of acute hepatitis B among adults with diagnosed diabetes mellitus

INTRODUCTION

The risk of acute hepatitis B among adults with diabetes mellitus is unknown. We investigated the association between diagnosed diabetes and acute hepatitis B.

METHODS

Confirmed acute hepatitis B cases were reported in 2009-2010 to eight Emerging Infections Program (EIP) sites; diagnosed diabetes status was determined. Behavioral Risk Factor Surveillance System respondents residing in EIP sites comprised the comparison group. Odds ratios (ORs) comparing acute hepatitis B among adults with diagnosed diabetes versus without diagnosed diabetes were determined by multivariate logistic regression, adjusting for age, sex, and race/ethnicity, and stratified by the presence or absence of risk behaviors for hepatitis B virus (HBV) infection.

RESULTS

During 2009-2010, EIP sites reported 865 eligible acute hepatitis B cases among persons aged ≥23 years; 95 (11.0%) had diagnosed diabetes. Comparison group diabetes prevalence was 9.1%. Among adults without hepatitis B risk behaviors and with reported diabetes status, the OR for acute hepatitis B comparing adults with and without diabetes was 1.9 (95% confidence interval [CI] = 1.4, 2.6); ORs for adults ages 23-59 and ≥60 years were 2.1 (95% CI = 1.6, 2.8) and 1.5 (95% = CI 0.9, 2.5), respectively.

CONCLUSIONS

Diabetes was independently associated with an increased risk for acute hepatitis B among adults without HBV risk behaviors.

The signal transducer and activator of transcription 6 gene (STAT6) increases the propensity of patients with atopic dermatitis toward disseminated viral skin infections

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with increased susceptibility to recurrent skin infections.

OBJECTIVE

We sought to determine why a subset of patients with AD have an increased risk of disseminated viral skin infections.

METHODS

Human subjects with AD with a history of eczema herpeticum (EH) and various control groups were enrolled. Vaccinia virus (VV) expression was measured by means of PCR and immunofluorescent staining in skin biopsy specimens from each study group after incubation with VV. Transgenic mice with a constitutively active signal transducer and activator of transcription 6 gene (STAT6) were characterized for response to VV skin inoculation. Genotyping for 10 STAT6 single nucleotide polymorphisms (SNPs) was performed in a white patient sample (n = 444).

RESULTS

VV gene and protein expression were significantly increased in the skin of patients with EH compared with other subject groups after incubation with VV in vitro. Antibody neutralization of IL-4 and IL-13 resulted in lower VV replication in patients with a history of EH. Mice that expressed a constitutively active STAT6 gene compared with wild-type mice had increased mortality and satellite lesion formation after VV skin inoculation. Significant associations were observed between STAT6 SNPs and EH (rs3024975, rs841718, rs167769, and rs703817) and IFN-γ production. The strongest association was observed for a 2-SNP haplotype (patients with AD with a history of EH vs patients with AD without a history of EH, 24.9% vs 9.2%; P = 5.17 × 10(-6)).

CONCLUSION

The STAT6 gene increases viral replication in the skin of patients with AD with a history of EH. Further genetic association studies and functional investigations are warranted.

Human atopic dermatitis complicated by eczema herpeticum is associated with abnormalities in IFN-γ response

BACKGROUND

The basis for increased susceptibility of patients with atopic dermatitis (AD) to develop disseminated viral skin infections such as eczema herpeticum (AD with a history of eczema herpeticum, ADEH(+)) is poorly understood.

OBJECTIVE

We sought to determine whether subjects with AD prone to disseminated viral skin infections have defects in their IFN responses.

METHODS

GeneChip profiling was used to identify differences in gene expression of PBMCs from patients with ADEH(+) compared with patients with AD without a history of eczema herpeticum (ADEH(-)) and nonatopic controls. Key differences in protein expression were verified by enzyme-linked immunosorbent spot assay and/or ELISA. Clinical relevance was further demonstrated by a mouse model of disseminated viral skin infection and genetic association analysis for genetic variants in IFNG and IFNGR1 and ADEH among 435 cases and controls.

RESULTS

We demonstrate by global gene expression analysis selective transcriptomic changes within the IFN superfamily of PBMCs from subjects with ADEH(+) reflecting low IFN-γ and IFN-γ receptor gene expression. IFN-γ protein production was also significantly lower in patients with ADEH(+) (n = 24) compared with patients with ADEH(-) (n = 20) and nonatopic controls (n = 20). IFN-γ receptor knockout mice developed disseminated viral skin infection after epicutaneous challenge with vaccinia virus. Genetic variants in IFNG and IFNGR1 single nucleotide polymorphisms (SNPs) were significantly associated with ADEH (112 cases, 166 controls) and IFN-γ production: a 2-SNP (A-G) IFNGR1 haplotype (rs10457655 and rs7749390) showed the strongest association with a reduced risk of ADEH+ (13.2% ADEH(+) vs 25.5% ADEH(-); P = .00057).

CONCLUSION

Patients with ADEH(+) have reduced IFN-γ production, and IFNG and IFNGR1 SNPs are significantly associated with ADEH(+) and may contribute to an impaired immune response to herpes simplex virus.

Vaccination of patients with mild and severe asthma with a 2009 pandemic H1N1 influenza virus vaccine

BACKGROUND

Asthma was the most common comorbidity of patients hospitalized with 2009 H1N1 influenza.

OBJECTIVE

We sought to assess the immunogenicity and safety of an unadjuvanted, inactivated 2009 H1N1 vaccine in patients with severe versus mild-to-moderate asthma.

METHODS

We conducted an open-label study involving 390 participants (age, 12-79 years) enrolled in October-November 2009. Severe asthma was defined as need for 880 μg/d or more of inhaled fluticasone equivalent, systemic corticosteroids, or both. Within each severity group, participants were randomized to receive intramuscularly 15 or 30 μg of 2009 H1N1 vaccine twice 21 days apart. Immunogenicity end points were seroprotection (hemagglutination inhibition assay titer ≥40) and seroconversion (4-fold or greater titer increase). Safety was assessed through local and systemic reactogenicity, asthma exacerbations, and pulmonary function.

RESULTS

In patients with mild-to-moderate asthma (n = 217), the 2009 H1N1 vaccine provided equal seroprotection 21 days after the first immunization at the 15-μg (90.6%; 95% CI, 83.5% to 95.4%) and 30-μg (95.3%; 95% CI, 89.4% to 98.5%) doses. In patients with severe asthma (n = 173), seroprotection 21 days after the first immunization was 77.9% (95% CI, 67.7% to 86.1%) and 94.1% (95% CI, 86.8% to 98.1%) at the 15- and 30-μg doses, respectively (P = .004). The second vaccination did not provide further increases in seroprotection. Participants with severe asthma who are older than 60 years showed the lowest seroprotection (44.4% at day 21) with the 15-μg dose but had adequate seroprotection with 30 μg. The 2 dose groups did not differ in seroconversion rates. There were no safety concerns.

CONCLUSION

Monovalent inactivated 2009 H1N1 pandemic influenza vaccine was safe and provided overall seroprotection as a surrogate of efficacy. In patients older than 60 years with severe asthma, a 30-μg dose might be more appropriate.

Attempted control of hyperglycemia during cardiopulmonary bypass fails to improve neurologic or neurobehavioral outcomes in patients without diabetes mellitus undergoing coronary artery bypass grafting

OBJECTIVE

Hyperglycemia worsens outcomes in critical illness. This randomized, double-blind, placebo-controlled clinical trial tested whether insulin treatment of hyperglycemia during cardiopulmonary bypass would reduce neurologic, neuro-ophthalmologic, and neurobehavioral outcomes after coronary artery bypass grafting.

METHODS

Three hundred eighty-one nondiabetic patients undergoing isolated coronary artery bypass grafting were given infusions of insulin or placebo when their blood glucose concentration exceeded 100 mg/dL during cardiopulmonary bypass. The primary outcome measure was the combined incidence of new neurologic, neuro-ophthalmologic, or neurobehavioral deficits or neurologic death observed at 4 to 8 days postoperatively. This same measure was assessed secondarily at 6 weeks and 6 months. Length of hospital stay was also compared as a secondary assessment.

RESULTS

The 2 groups were well matched at baseline. The insulin-treated group had significantly lower blood glucose concentrations during bypass. Sixty-six percent of subjects in the insulin-treated group and 67% of subjects in the control group demonstrated a new or worsening neurologic, neuro-ophthalmologic, or neurobehavioral deficit or neurologic death at the 4- to 8-day assessment. Outcomes were also similar in the 2 groups at 6 weeks (37% and 39% incidence, respectively) and 6 months (30% and 25%, respectively). Median lengths of stay were 7 and 6 days, respectively, in the treatment and control groups. None of these outcome differences was statistically significant.

CONCLUSION

Attempted control of hyperglycemia during cardiopulmonary bypass had no significant effect on the combined incidence of neurologic, neuro-ophthalmologic, or neurobehavioral deficits or neurologic death and failed to shorten the length of hospital stay. These results do not contradict those of other studies showing that aggressive control of hyperglycemia in the postoperative period will improve outcome.

The impact of pedigree structure on heritability estimates for pulse pressure in three studies

OBJECTIVES

Pulse pressure (PP) is a measure of large artery stiffness and has been shown to be an important predictor of cardiovascular morbidity and mortality. The aims of the present study were to investigate the heritability of PP in three studies, the Diabetes Heart Study (DHS), the Insulin Resistance Atherosclerosis Family Study (IRAS FS), and the NHLBI Family Heart Study (FHS), to estimate the residual heritability after inclusion of a common set of covariates, and to investigate the impact of pedigree structure on estimating heritability.

METHODS AND RESULTS

DHS is primarily a sibling pair nuclear family study design, while both IRAS FS and FHS have large pedigrees. Heritability estimates of log-transformed PP were obtained using variance component models. After adjusting for age, gender, ethnicity/center, height, diabetes status, and mean arterial pressure (MAP), heritability estimates of PP were 0.40 +/- 0.08 , 0.22 +/- 0.05, and 0.19 +/- 0.03 in DHS, IRAS FS, and FHS, respectively. The heritability estimate from DHS was significantly different from both IRAS FS and FHS (both p values <0.05). A random re-sampling technique (modified bootstrap) was used to explore the heritability in the IRAS FS and FHS data when these pedigrees were trimmed to mimic the DHS pedigree structure. The re-sampling method (mimicking a sibling pair nuclear family design in all studies) yielded PP heritability estimates of 0.37, 0.34, and 0.27 in DHS, IRAS FS, and FHS, respectively. There was no significant difference among the heritability estimates from the three studies based on the re-sampling method.

CONCLUSION

We have shown that PP has a moderately heritable component in three different studies. These data illustrate the influence of pedigree structure can have on estimating heritability. Thoughtful comparisons of heritability estimates must consider study design factors such as pedigree structure.

Site-specific progression of carotid artery intimal-medial thickness

PURPOSE

To characterize the intercorrelation of changes in intimal-medial thickness (IMT) among carotid artery sites and examine the influence of diabetes and sex on these correlations.

METHODS

Ultrasonographic IMT measurements from the near and far walls of common and internal segments in the arteries of 1207 participants of the Insulin Resistance Atherosclerosis Study (IRAS) were analyzed to estimate the underlying correlations of IMT changes (average of 5.2 years) among artery sites after correction for measurement error.

RESULTS

Differences in IMT progression associated with diabetes and sex were evident at all sites. IMT changes were strongly correlated between left and right arteries (r=0.32-0.73) and near and far walls (r=0.42-0.87). Correlations of IMT changes at corresponding sites of internal versus common segments were reduced from r=0.32 among normal individuals to r=0.09 among those with diabetes, but were similar for women and men.

CONCLUSIONS

IMT progression is a diffuse process involving all carotid artery sites. Diabetes does not influence the bilateral and radial nature of progression, but reduces the correlation between distal sites within an artery. Pooling measurements across arteries and walls often yields the most efficient analyses.

Minimal model-based insulin sensitivity has greater heritability and a different genetic basis than homeostasis model assessment or fasting insulin

Insulin resistance is an important risk factor for development of type 2 diabetes as well as other chronic conditions, including hypertension, cardiovascular disease, and colon cancer. To find genes for insulin resistance it is necessary to assess insulin action in large populations. We have previously measured insulin action in a large cohort of subjects (Insulin Resistance and Atherosclerosis Study [IRAS] Family Study) using the minimal model approach. In this study, we compare sensitivity from the minimal model (insulin sensitivity index [S(I)]) with the measure of insulin resistance emanating from the homeostasis model assessment (HOMA) approach. The former measure emerges from the glycemic response to endogenous and exogenous insulin; the latter is based solely on fasting measures of glucose and insulin. A total of 112 pedigrees were represented, including 1,362 individuals with full phenotypic assessment. Heritability of S(I) was significantly greater than that for HOMA (0.310 vs. 0.163) and for fasting insulin (0.171), adjusted for age, sex, ethnicity, and BMI. In addition, correlation between S(I) and either HOMA or fasting insulin was only approximately 50% accounted for by genetic factors, with the remainder accounted for by environment. Thus S(I), a direct measure of insulin sensitivity, is determined more by genetic factors rather than measures such as HOMA, which reflect fasting insulin.

An integrated population-averaged approach to the design, analysis and sample size determination of cluster-unit trials

While the mixed model approach to cluster randomization trials is relatively well developed, there has been less attention given to the design and analysis of population-averaged models for randomized and non-randomized cluster trials. We provide novel implementations of familiar methods to meet these needs. A design strategy that selects matching control communities based upon propensity scores, a statistical analysis plan for dichotomous outcomes based upon generalized estimating equations (GEE) with a design-based working correlation matrix, and new sample size formulae are applied to a large non-randomized study to reduce underage drinking. The statistical power calculations, based upon Wald tests for summary statistics, are special cases of a general power method for GEE.

Metabolic predictors of 5-year change in weight and waist circumference in a triethnic population: the insulin resistance atherosclerosis study

Insulin resistance, insulin secretion, and glucose tolerance may predict weight change. A total of 1,194 adults aged 39-69 years at baseline (46% with normal glucose tolerance according to World Health Organization criteria, 23% with impaired glucose tolerance, and 31% with type 2 diabetes mellitus who were not taking insulin) were evaluated at baseline (1992-1994) and after 5 years. Baseline insulin sensitivity (S(I)) was measured by means of a 12-sample, insulin-enhanced, frequently sampled intravenous glucose tolerance test. Insulin secretion was assessed in terms of acute insulin response and disposition index, both obtained from the frequently sampled intravenous glucose tolerance test. At follow-up, 25% of subjects had lost more than 2.27 kg (>5 pounds), 38% weighed within 2.27 kg of their baseline weight, and 37% had gained more than 2.27 kg. In separate models, greater weight loss occurred among those with type 2 diabetes than among those with either impaired glucose tolerance or normal glucose tolerance (p < 0.001); baseline acute insulin response and disposition index were positively associated and baseline fasting insulin level was inversely associated with 5-year weight change (p < 0.05 for each; data were adjusted for baseline body mass index and demographic and behavior change variables). Upon simultaneous inclusion of metabolic variables within glucose tolerance status groups, none was a significant predictor of weight loss. Apart from glucose tolerance status itself, measures of insulin metabolism appear to have little effect on weight change over 5 years.

Ethnic and racial differences in diabetes care: The Insulin Resistance Atherosclerosis Study

OBJECTIVE

Diabetes and its complications disproportionately affect African Americans and Hispanics. Complications could be prevented with appropriate medical care. We compared five processes of care and three outcomes of care among African Americans, Hispanics, and non-Hispanic whites.

RESEARCH DESIGN AND METHODS

We used data from the Insulin Resistance Atherosclerosis Study (1993-1998) of participants with known diabetes. African Americans and Hispanics were compared with non-Hispanic whites from the same region. Five process measures (treatment of diabetes, hypertension, hyperlipidemia, albuminuria, and coronary artery disease) and three outcome measures (control of diabetes, hypertension, and hyperlipidemia) were evaluated.

RESULTS

Comparison groups were similar in baseline characteristics. African Americans and Hispanics were equally likely as their non-Hispanic white comparison group to receive treatment for diabetes, hypertension, hyperlipidemia, albuminuria, and coronary artery disease, although treatment rates for hyperlipidemia and albuminuria were poor for all groups. African Americans were more likely to have poorly controlled diabetes (HbA(1c) >8.0%: OR 2.23, 95% CI 1.26-3.94). Both African American and Hispanics were significantly more likely to have borderline or poorly controlled hypertension than non-Hispanic whites (blood pressure >130-140/85-90 or >140/90 mmHg: African American/non-Hispanic white OR 3.22, 95% CI 1.57-6.59; Hispanic/non-Hispanic white 3.14, 1.35-7.3).

CONCLUSIONS

The rates of treatment for diabetes and associated comorbidities are similar across all three ethnic groups. Few individuals in any ethnic group received treatment for hyperlipidemia and albuminuria. Ethnic disparities exist in control of diabetes and hypertension. Programs should be tested to improve overall quality of care and eliminate these disparities.

Insulin sensitivity and the risk of incident hypertension: insights from the Insulin Resistance Atherosclerosis Study

OBJECTIVE

The insulin resistance syndrome has been described as including hypertension. Previous studies have documented cross-sectional associations between insulin sensitivity (S(I)) and blood pressure or prevalent hypertension. Prospective data have been sparse.

RESEARCH DESIGN AND METHODS

The Insulin Resistance Atherosclerosis Study (IRAS) is a prospective study of the associations of S(I) with atherosclerosis and other risk factors for cardiovascular disease. We examined the association between S(I), measured using the frequently sampled intravenous glucose tolerance test with minimal model analysis, and incident hypertension (defined as per the Joint National Committee), at the 5-year examination in 840 IRAS participants who were free of hypertension at the baseline examination.

RESULTS

Adjusted for age, sex, ethnicity, and smoking status, for each unit greater S(I), the risk of hypertension was 10% lower (95% CI 2-19, P < 0.05).

CONCLUSIONS

These findings, from a prospective study, support the presence of a modest protective association between greater S(I) and lower risk of hypertension. These findings support the contention that interventions that improve S(I) may be beneficial with respect to the development of hypertension and cardiovascular disease. This contention should be tested in randomized clinical trials.

A randomized, controlled trial comparing long-term and short-term exercise in patients with chronic obstructive pulmonary disease

PURPOSE

To compare the effects of short-term (3 months) and long-term (18 months) involvement in an exercise program on self-reported disability and physical function in patients with chronic obstructive pulmonary disease (COPD).

METHODS

A total of 140 patients with COPD were studied in a randomized, single-blinded clinical trial. Self-reported disability and physical function were assessed using a 21-item questionnaire, a 6-minute walk, timed stair climb, and an overhead task.

RESULTS

At the completion of the trial, participants in the long-term intervention reported 12% less disability than those in the short-term intervention (adjusted mean with 95% confidence interval, 1.53 (1.43-1.63) versus 1.71 (1.61 to 1.81) units, respectively; P=.016), walked 6% farther during 6-minutes (1,815.0 [1,750.4-1,879.6] vs 1,711.5 [1,640.7-1,782.3] feet, respectively), climbed steps 11% faster (11.6 [11.0-12.2] vs 12.9 [12.3-13.5] seconds, respectively), and completed an overhead task 8% faster (46.8 [44.4-49.2] vs 50.4 [47.8-53.0] seconds, respectively) than those in the short-term intervention.

CONCLUSION

An 18 month exercise program results in greater improvements in self-reported disability and physical function in patients with COPD when compared with a 3-month exercise program. As such, long-term exercise should be recommended for all patients with COPD.

Plasma and dietary vitamin E in relation to incidence of type 2 diabetes: The Insulin Resistance and Atherosclerosis Study (IRAS)

OBJECTIVE

To evaluate the association of vitamin E with incidence of type 2 diabetes and to do so separately among individuals who did and those who did not report regular use of vitamin supplementation.

RESEARCH DESIGN AND METHODS

The Insulin Resistance Atherosclerosis Study (IRAS) included 895 nondiabetic adults at baseline (including 303 with impaired glucose tolerance [IGT]), 148 of whom developed type 2 diabetes according to World Health Organization (WHO) criteria during the 5-year follow-up. At baseline, dietary vitamin E was estimated by a validated food frequency interview, usual supplement use was confirmed by supplement label, and plasma alpha-tocopherol was measured. Analyses were conducted separately for individuals who did (n = 318) and did not (n = 577) use vitamin E supplements.

RESULTS

Among supplement nonusers, reported mean intake of vitamin E (mg alpha-tocopherol equivalents [alpha-TE]) did not differ between those who remained nondiabetic (n = 490) and those who developed diabetes (n = 87) (10.5 +/- 5.5 vs. 9.5 +/- 4.8 [means +/- SD], respectively, NS). After adjustment for demographic variables, obesity, physical activity, and other nutrients, the association remained nonsignificant (odds ratio [OR] 0.80, 95% CI 0.13-5.06) for the highest level of intake (> or =20 mg alpha-TE) compared with the lowest level (1-4 alpha-TE). However, results for plasma concentration of alpha-tocopherol showed a significant protective effect both before and after adjustment for potential confounders (adjusted OR 0.12, 95% CI 0.02-0.68, for the highest quintile vs. the lowest quintile; overall test for trend, P < 0.01). Among individuals who reported habitual use of vitamin E supplements (at least once per month in the year before baseline; 259 remained nondiabetic and 59 developed diabetes), no protective effect was observed for either reported intake of vitamin E or plasma concentration of alpha-tocopherol

CONCLUSIONS

A protective effect of vitamin E may exist within the range of intake available from food. This effect may go undetected within studies of high-dose supplement use, which appears to hold no additional protective benefit.

Caloric restriction lowers plasma lipoprotein (a) in male but not female rhesus monkeys

Many age-associated pathophysiological changes are retarded by caloric restriction (CR). The present study has investigated the effect of CR on plasma lipoprotein (a) [Lp(a)], an independent risk factor for the age-associated process of atherosclerosis. Rhesus monkeys were fed a control diet (n=19 males, 12 females) or subjected to CR (n=20 males, 11 females fed 30% less calories) for >2 years. All female animals were premenopausal. Plasma Lp(a) levels in control animals were almost two fold higher for males than females (47+/-9 vs 25+/-5mg/dl mean+/-SEM, p=0.05). CR resulted in a reduction in circulating Lp(a) in males to levels similar to those measured in calorie-restricted females, (27+/-5 vs 24+/-4 mg/dl mean+/-SEM). For all animals, plasma Lp(a) was correlated with total cholesterol (r=0.27, p=0.03) and LDL cholesterol (r=0.50, p=0.0001) whether unadjusted or after adjustment for treatment, gender or group. These studies introduce a new mechanism whereby CR may have a beneficial effect on risk factors for the development of atherosclerosis in primates.

Tobacco growers' knowledge of revenue distribution and foreign prices: implications for health education

This study examined tobacco growers' knowledge of tobacco economics, particularly their knowledge of how tobacco revenue is distributed and their knowledge of the price of foreign tobacco. Tobacco growers (n = 1236) from 14 tobacco-dependent counties in North Carolina were interviewed by telephone and asked to estimate how much of a hypothetical $2.00 for a pack of cigarettes is received by each of four market segments: tobacco growers, retailers, government and manufacturers. Respondents were also asked to estimate the price of foreign raw tobacco. USDA data were used to assess the accuracy of the respondents' estimates. Respondents were within the 'correct' range as follows: growers 31%, retailers 15%, government 23%, manufacturers 43% and foreign prices 25%. Knowledge was positively related to education and farm size for the growers' share and foreign tobacco prices. Knowledge of the government's and manufacturers' shares was positively associated with younger age. North Carolina growers lacked knowledge of the distribution of the tobacco dollar. This may influence the positions that growers take on health policy and provide significant opportunities for health educators to become involved in grassroots efforts to educate growers.

Cigarette smoking, low birth weight, and preterm births in low-income African American women

OBJECTIVE

To examine effects of light and heavy cigarette smoking on the incidence of low birth weight (LBW) and preterm births in African American women.

DESIGN

A total of 1146 low-income African American women participated in a randomized trial to test the effectiveness of nursing intervention in the reduction of preterm and LBW births. This secondary analysis focused on the effects of cigarette smoking on LBW (< 2500 gm) and preterm (< 37 weeks' gestation) births.

RESULTS

Cigarette smoking had a significant effect on both LBW and preterm births. When light smokers were compared with nonsmokers, odds ratios were 1.89 (confidence interval (CI) 1.15, 3.13; p = 0.0127) for LBW births and 1.74 (CI 1.00; 3.02; p = 0.0499) for preterm births. When heavy smokers were compared with nonsmokers, odds ratios were 3.03 (CI 1.90, 4.86; p = 0.001) for LBW births and 2.60 (CI 1.55, 4.35; p = 0.0003) for preterm births.

CONCLUSION

Cigarette smoking was associated with significantly higher rates of both LBW and preterm births in this sample of African American women.

Evaluating and understanding performance testing in COPD patients

PURPOSE

There is increasing interest in the use of performance tests to assess physical function among patients with debilitating diseases. The purpose of this study was to describe the measurement properties of a performance test battery used in the Reconditioning Exercise and Chronic Obstructive Pulmonary Disease Trial and to explore how well-selected physiologic and psychosocial measures explained test performance.

METHODS

To assess test-retest reliability of the performance tests, older patients with chronic obstructive pulmonary disease (n = 30) completed, on two different occasions, a 6-minute walk for distance, a timed stair climb, and a timed elevated-arm task. In addition, stepwise regression analyses were conducted on a larger sample (n = 209) to examine how effective conceptually relevant physiologic and psychosocial variables were at explaining variation in task performance.

RESULTS

Results showed that all three performance tasks had good test-retest reliability (all coefficients > 0.80) and shared variance in expected directions with VO2peak, forced expiratory volume in 1 second (FEV1), and self-reported disability. Regression analyses suggest that VO2peak, FEV1, self-efficacy, and self-reported disability are important variables to consider in attempts to understand performance-related disability in patients with chronic obstructive pulmonary disease (COPD).

CONCLUSIONS

The physical performance test battery appears to be a reliable means of assessing physical functioning in older patients with COPD. Furthermore, findings support the important role that VO2peak plays in task performance and suggest that patients' perceptions should be given careful consideration when attempting to understand physical decline in clinical settings.

The relation of proinsulin and insulin to insulin sensitivity and acute insulin response in subjects with newly diagnosed type II diabetes: the Insulin Resistance Atherosclerosis Study

AIMS/HYPOTHESIS

Proinsulin concentrations are increased relative to insulin concentrations in subjects with Type II (non-insulin-dependent) diabetes mellitus. This could be secondary to hyperglycaemia or insulin resistance or due to a defect in insulin secretion.

METHODS

We investigated the association between fasting insulin, intact proinsulin and the intact proinsulin: insulin ratio with insulin sensitivity, estimated by a frequently sampled intravenous glucose tolerance test and the minimal model and with acute insulin response (AIR) in 182 newly diagnosed Type II diabetic subjects aged 40 to 69 years. None of the subjects was receiving hypoglycaemic medication.

RESULTS

Insulin sensitivity correlated inversely with fasting insulin (r(s) = -0.42) and intact proinsulin (r(s) = -0.32) (p < 0.001). The intact proinsulin:insulin ratio was not correlated with insulin sensitivity. AIR correlated positively with intact proinsulin (r(s) = 0.23) and inversely with the intact proinsulin:insulin ratio (r(s) = -0.29, p < 0.001). Fasting glucose correlated positively with intact proinsulin (r(s) = 0.34) and the intact proinsulin:insulin ratio (r(s) = 0.24, p < 0. 001). The intact proinsulin:insulin ratio increased by decreasing AIR (quartiles of AIR from high to low: 7.8, 8.2, 9.7 and 12.1 %, p < 0.001). This association was independent of age, sex, ethnicity, body mass index, fasting glucose, and insulin sensitivity.

CONCLUSION/INTERPRETATION

Insulin resistance (low insulin sensitivity) was not related to the intact proinsulin:insulin ratio in subjects with Type II diabetes. In contrast, both low AIR and high fasting glucose concentrations were associated with a disproportionate increase in proinsulin concentration. These results suggest that increased intact proinsulin:insulin ratio is a marker of a defect in insulin secretion in Type II diabetic subjects.

Relative contribution of insulin and its precursors to fibrinogen and PAI-1 in a large population with different states of glucose tolerance. The Insulin Resistance Atherosclerosis Study (IRAS)

Hyperinsulinemia is associated with the development of coronary heart disease. However, the underlying mechanisms are still poorly understood. Hypercoagulability and impaired fibrinolysis are possible candidates linking hyperinsulinism with atherosclerotic disease, and it has been suggested that proinsulin rather than insulin is the crucial pathophysiological agent. The aim of this study was to investigate the relationship of insulin and its precursors to markers of coagulation and fibrinolysis in a large triethnic population. A strong and independent relationship between plasminogen activator inhibitor-1 (PAI-1) antigen and insulin and its precursors (proinsulin, 32-33 split proinsulin) was found consistently across varying states of glucose tolerance (PAI-1 versus fasting insulin [proinsulin], r=0.38 [r=0.34] in normal glucose tolerance; r=0.42 [r=0.43] in impaired glucose tolerance; and r=0.38 [r=0.26] in type 2 diabetes; all P<0.001). The relationship remained highly significant even after accounting for insulin sensitivity as measured by a frequently sampled intravenous glucose tolerance test. In a stepwise multiple regression model after adjusting for age, sex, ethnicity, and clinic, both insulin and its precursors were significantly associated with PAI-1 levels. The relationship between fibrinogen and insulin and its precursors was significant in the overall population (r=0.20 for insulin and proinsulin; each P<0.001) but showed a more inconsistent pattern in subgroup analysis and after adjustments for demographic and metabolic variables. Stepwise multiple regression analysis showed that proinsulin (split products) but not fasting insulin significantly contributed to fibrinogen levels after adjustment for age, sex, clinic, and ethnicity. Decreased insulin sensitivity was independently associated with higher PAI-1 and fibrinogen levels. In summary, we were able to demonstrate an independent relationship of 2 crucial factors of hemostasis, fibrinogen and PAI-1, to insulin and its precursors. These findings may have important clinical implications in the risk assessment and prevention of macrovascular disease, not only in patients with overt diabetes but also in nondiabetic subjects who are hyperinsulinemic.

Relationships between insulin resistance and lipoproteins in nondiabetic African Americans, Hispanics, and non-Hispanic whites: the Insulin Resistance Atherosclerosis Study

The study purpose was to explore the association between dyslipidemia and insulin resistance in three ethnic groups. The Insulin Resistance Atherosclerosis Study (IRAS) is a multicenter epidemiologic study conducted at four clinical centers in California, Texas, and Colorado. The study population for this analysis consisted of 931 non-Hispanic white, African American, and Hispanic men and women (aged 45 to 64 years) without diabetes. The IRAS clinical examinations included lipoprotein measures, a 75-g glucose tolerance test, and the frequently sampled intravenous glucose tolerance (FSIGT) test. The results show a consistent relationship between insulin-mediated glucose disposal and dyslipidemia in African American, Hispanic, and non-Hispanic white men and women. Further, LDL size was inversely associated with insulin resistance in all three ethnic groups. These findings indicate that dyslipidemia is a fundamental part of the insulin resistance syndrome in all of the ethnic groups studied.

Microalbuminuria is associated with insulin resistance in nondiabetic subjects: the insulin resistance atherosclerosis study

Microalbuminuria is associated with excess cardiovascular mortality in both diabetic and nondiabetic subjects. Patients with NIDDM and microalbuminuria are more insulin resistant than those without microalbuminuria. However, the relationship between insulin resistance and microalbuminuria in patients with NIDDM could be due to hyperglycemia, which can cause both insulin resistance and an increase in albumin excretion rate. Little is known about microalbuminuria and insulin resistance in nondiabetic subjects. Therefore, we examined, cross-sectionally, the relationship of insulin sensitivity (S(I) x 10(-4) min x microU(-1) x ml(-1)), estimated by a frequently sampled intravenous glucose tolerance test and the minimal model and fasting plasma insulin concentration, to microalbuminuria (albumin-to-creatinine ratio > or = 2 mg/mmol) in 982 nondiabetic subjects aged 40-69 years. Altogether, 15% of the subjects had microalbuminuria, and 32% had hypertension. Subjects with microalbuminuria had a lower degree of insulin sensitivity (means +/- SE, 1.70 +/- 0.11 vs. 2.25 +/- 0.07, P = 0.003) and higher fasting insulin concentrations (17.4 +/- 1.1 vs. 15.7 +/- 0.5 mU/l, P = 0.059) compared with subjects without microalbuminuria. In logistic regression analysis, an increasing degree of insulin sensitivity was related to a decreasing prevalence of microalbuminuria (odds ratio = 0.86, 95% CI: 0.79-0.94, P < 0.001). Although this relationship attenuated after adjustment for age, sex, ethnicity, hypertension, fasting glucose, and BMI, it still remained significant. The association between insulin sensitivity and microalbuminuria was shown not to be different between normotensive and hypertensive subjects. Our results suggest a relationship between insulin resistance and microalbuminuria in nondiabetic subjects that is partially dependent on blood pressure, glucose levels, and obesity.

A randomized trial of nurse intervention to reduce preterm and low birth weight births

OBJECTIVE

To test the effect of telephone calls from registered nurses to low-income pregnant women on the rates of low birth weight (LBW) and preterm births.

METHODS

A total of 1554 women receiving prenatal care in a public clinic who met study criteria and who consented were assigned randomly to intervention and control groups. Women in the intervention group received telephone calls from a registered nurse, one or two times weekly from 24 weeks' through 37 weeks' gestation. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Low birth weight rates were 10.9% in the intervention group and 14.0% in the control group (RR 0.75; 95% CI 0.55, 1.03; P = .072). For gestational age less than 37 weeks, rates were 9.7 in the intervention group and 11.0 in the control group (RR .87; 95% CI 0.62, 1.22; P = .415). In the subgroup of low-income black women 19 years of age and older, a statistically significant difference was found in preterm birth rates before 37 weeks (8.7% in the intervention group versus 15.4% in the controls [RR 0.56; 95% CI 0.38, 0.84; P = .004]).

CONCLUSION

There was no difference in LBW or preterm births between intervention and control groups in the total sample. In a secondary analysis of black subjects 19 years of age and older, there was a significant difference in preterm birth rates.

Predictors of crop diversification: a survey of tobacco farmers in North Carolina (USA)

OBJECTIVE

To assess the attitudes and behaviours of North Carolina tobacco farmers around crop diversification.

DESIGN

Cross-sectional telephone survey.

PARTICIPANTS

Active tobacco farmers in 14 North Carolina counties (n = 1236), interviewed between January and April 1997 (91% response rate).

OUTCOME MEASURES

Interest in, experience with, and perceived barriers to diversification.

RESULTS

Most farmers (95%) grew/raised a commodity other than tobacco (mean = 2.8). A total of 60% of farmers expressed interest in trying other on-farm activities to supplement their tobacco and 60% reported taking action in the past year around supplementation. Younger age and college education were positively associated with interest. College education, off-farm income, and larger farm size were associated with the number of actions taken. For perceived external barriers to diversification, use of tobacco, percent income from tobacco, lack of college education, and younger age were most strongly associated with the number of barriers. For internal barriers (personal factors), percent income from tobacco, use of tobacco, and lack of college education were most strongly associated with the number of barriers.

CONCLUSIONS

Most farmers were involved in diverse operations and expressed interest in continuing to diversify, although the breadth of diversification was narrow. Farmers noted many barriers to diversifying. If conventional production and marketing techniques are employed for non-tobacco alternatives, these alternatives may not provide the sustainable profitability that tobacco has afforded. Competition from foreign tobacco growers is the primary threat to the future of American growers and tobacco dependent communities.

Microalbuminuria and carotid artery intima-media thickness in nondiabetic and NIDDM subjects. The Insulin Resistance Atherosclerosis Study (IRAS)

BACKGROUND AND PURPOSE

Microalbuminuria is associated with cardiovascular mortality in subjects with non-insulin-dependent diabetes mellitus (NIDDM). However, little is known about this association in nondiabetic subjects. Specifically, it is not known whether microalbuminuria is related to an early stage of atherosclerosis manifested as increased intima-media thickness (IMT) of carotid arteries. We investigated the relationship between microalbuminuria and carotid artery IMT in 991 nondiabetic and 450 NIDDM subjects aged 40 to 69 years.

METHODS

Microalbuminuria was defined as albumin-to-creatinine ratio > or = 2 mg/mmol in a morning spot urine sample. B-mode ultrasound was used to assess the IMT of the common and internal carotid arteries.

RESULTS

Altogether 13.9% of nondiabetic and 27.6% of NIDDM subjects had microalbuminuria, and 31.1% of nondiabetic and 50.8% of NIDDM subjects had hypertension. Subjects with microalbuminuria had greater common carotid artery (CCA) IMT than those without microalbuminuria (nondiabetic: 0.84 +/- 0.02 versus 0.80 +/- 0.01 mm, P = .010; NIDDM: 0.89 +/- 0.02 versus 0.86 +/- 0.01 mm, P = .152; combined: 0.86 +/- 0.01 versus 0.82 +/- 0.01, P = .005). The association of microalbuminuria and CCA IMT was independent of age, sex, ethnicity, smoking, and lipoprotein levels. Although further adjustment for hypertension in the multivariate linear regression analysis attenuated the difference in CCA IMT between subjects with and without microalbuminuria, this difference continued to be significant (combined: 0.86 +/- 0.01 versus 0.83 +/- 0.01, P = .015). In contrast to CCA IMT, microalbuminuria was not related to ICA IMT.

CONCLUSIONS

Microalbuminuria was associated with increased CCA IMT. This relationship was only partly mediated by hypertension. Thus, microalbuminuria is related to atherosclerosis at an early stage of the disease process.

Ratings of students' performances in a third-year internal medicine clerkship: a comparison between problem-based and lecture-based curricula

PURPOSE

To compare clinical performances in a third-year medicine clerkship between studies from a problem-based learning (PBL) curriculum and students from a traditional, lecture-based learning (LBL) curriculum.

METHOD

The study participants were 88 PBL students and 364 LBL students rotating through a common third-year internal medicine clerkship at the Bowman Gray School of Medicine at Wake Forest University, classes of 1991-1995. Faculty and housestaff assessed the students' performances using four clinical rating scales. The student also completed the medicine student ("shelf") test of the National Board of Medical Examiners (NBME).

RESULTS

On average, the PBL students received significantly higher ratings from housestaff and faculty on all four rating scales. No difference in scores on the NBME medicine shelf test was observed.

CONCLUSION

The results support the hypothesis that preclinical PBL curricula as found at the Bowman Gray School of Medicine may enhance third-year students' clinical performances.

Interpretation of fracture follow-up roentgenograms: is a second opinion routinely necessary?

To determine whether a second interpretation of follow-up roentgenograms is necessary in fracture management, we analyzed 300 fracture follow-up visits to two orthopaedists with regard to the efficacy of obtaining a radiologist's interpretation of the follow-up films. Fracture management decisions were made at the time of the visit without the benefit of the radiologist's interpretation of the films. Both the clinic note and the radiologist's official report of the x-ray films were independently compared by two "blinded" physician observers. Major discrepancies were defined as those warranting an alteration of treatment plan. Only one major discrepancy was found, judged by both observers to be an incorrect interpretation by the radiologist. No major discrepancies were found in the treating physician's interpretation. The maximal prevalence of discrepancy was less than 1%. We conclude that the need for a second interpretation of routine fracture follow-up x-rays is questionable from the standpoint of quality of care.

Insulin-like growth factor-I is related to glycemic control in children and adolescents with newly diagnosed insulin-dependent diabetes

To address the relationship of insulin-like growth factor-I (IGF-I) to diabetes control, we determined IGF-I levels in 137 subjects age 17 yr and younger with recently diagnosed insulin-dependent diabetes mellitus in a population-based cohort study between 3 and 11 months after diagnosis (mean 4.9 months). Initial determinations of IGF-I, 24-h urine C-peptide and microalbuminuria, age, sex, height, weight, body mass index, pubertal stage, and glycosylated hemoglobin (GHb) were obtained. IGF-I levels ranged from 11-439 ng/mL, were strongly related to age (r = 0.74, P < 0.001), and were higher in females than males at any given age (P < 0.01). IGF-I was inversely related to GHb (partial r = -0.43, P < 0.001) after adjustment for sex and age. The relationship between IGF-I and GHb did not change between age groups (< 6, 6-9, > or = 10 yr of age; P = 0.50), and it did not change between prepubertal and pubertal subjects (P = 0.95). IGF-I was not related to 24-h urine C-peptide or microalbuminuria. These results suggest that lower IGF-I levels are related to poorer metabolic control of diabetes in the period following insulin-dependent diabetes mellitus diagnosis in all young persons regardless of age or pubertal status.

Blood lead levels in North Carolina painters

1. Blood lead levels were examined in 127 housepainters in North Carolina between April and September, 1993. Each participant filled out a questionnaire and gave a blood sample. The questionnaire covered the individual's work history, concentrating on paint-removal activities and personal protection, and also covered potential nonoccupational sources of lead exposure. Blood samples were analysed for lead content using atomic absorption spectroscopy. 2. The geometric mean blood lead level was 0.33 mumol L-1 (6.8 micrograms dL-1). No blood lead samples were found to exceed the occupational standard of 1.93 mumol L-1 (40 micrograms dL-1). The three highest samples had levels between 0.97 and 1.45 mumol L-1 (20 and 30 micrograms dL-1); this represented 2.4% of the study sample. 3. No statistical association was found between blood lead levels in these painters and their painting activities, including using dust masks for personal protection. 4. Current painting practices in this group of North Carolina painters do not appear to elevate blood lead levels above the occupational standard.

Antibiotic resistance in staphylococci adherent to cortical bone

The surface-adherent mode of bacterial growth has been shown to play a pivotal role in the persistent nature of infections involving retained foreign bodies, biomaterials, or dead bone (e.g., osteomyelitis). The hypothesis tested herein is that bone and implant materials--polytetrafluoroethylene (PTFE), and polymethylmethacrylate (PMMA)--provide a surface environment that promotes a type of bacterial growth characterized by an enhanced antibiotic resistance. The antibiotic resistance estimates of three staphylococcal subtypes were determined for organisms grown in an adherent state on the aforementioned surfaces as well as in their nonadherent or suspended state. Antibiotic resistance was found to vary with mode of bacterial growth. Secondly, for the staphylococcal subtypes, antibiotics and modes of growth studied herein, adherent growth on bone was associated with the most antibiotic resistance.

Glycemic control in early IDDM. The Wisconsin Diabetes Registry

OBJECTIVE

A cohort (n = 277) was followed from diabetes diagnosis to evaluate longitudinal glycemic control, urinary C-peptide levels, and certain features of diabetes self-management.

RESEARCH DESIGN AND METHODS

Unselected cases with IDDM, who were less than 30 yr of age, were identified at diagnosis from a 28-county area in Wisconsin. Subjects were asked to submit blood every 4 mo for GHb testing, to report aspects of diabetes self-management every 6 mo, and to collect a 24-h urine specimen 4 mo after diagnosis.

RESULTS

In the 1st yr of diabetes, the rate of increase (0.23%/mo) in GHb was significant for the cohort (P less than 0.001) and for almost all age and sex subgroups. In the 2nd yr, there was no significant rate of increase for the cohort as a whole (P greater than 0.10). Adolescent males (10-19 yr of age) had a mean GHb level for year 2 higher than males of other age-groups and higher than female adolescents (P less than 0.001). Adolescent males had a significant rate of increase in GHb for year 2 (P = 0.02), unlike all other age and sex subgroups. Adolescents had higher initial 24-h urine C-peptide levels than children less than 10 yr of age (P less than 0.01). During the 2nd yr of diabetes, the percentage of adolescent males reporting three or more insulin injections/day was lower than any other subgroup.

CONCLUSIONS

These data-suggest that glycemic control stabilizes during the 2nd yr of IDDM, except in adolescent males, and that this may be due partly to aspects of self-management.