Association between fear of hypoglycemia and physical activity in youth with type 1 diabetes: The SEARCH for diabetes in youth study

BACKGROUND

Youth with type 1 diabetes (T1D) are encouraged to participate in physical activity (PA). Studies have identified fear of hypoglycemia (FOH) as a barrier to participating in PA.

OBJECTIVES

To examine (a) PA patterns in youth with T1D by age group and (b) the relationship between both parental and youth FOH and youth PA.

METHODS

A cross-sectional analysis from the SEARCH cohort study visit of youth ages 10 to 17 years with T1D (n = 1129) was conducted. Linear regression models estimated the association between self-reported number of days of vigorous PA (VPA) and moderate PA (MPA) and both youth- and parent-reported FOH. Multivariable models were adjusted for age, sex, race, duration of T1D, HbA1c, use of continuous glucose monitoring (CGM), recent severe hypoglycemia, primary insulin regimen, and BMI.

RESULTS

Participants were 52% female, had mean (sd) age 14.4 (4.2) years, diabetes duration 7.5 years (1.8), HbA1c 9.2% (1.7). Older youth were less likely to engage in VPA (P < .01), or sports teams (P < .01), but more likely to engage in MPA (P < .01). Higher youth FOH (behavior subscale) was associated with increased levels of VPA (β (se) 0.30 (0.11), P = .01) but not significantly associated with MPA (P = .06). There was no statistically significant association between parental FOH and youth PA.

CONCLUSIONS

In SEARCH participants with T1D, VPA, and team sports participation declined with age, while MPA increased. We observed that higher scores on the youth FOH behavioral subscale were associated with increased VPA levels, suggesting that FOH may be less of a barrier to PA than previously thought.

Impact of glycemic control on heart rate variability in youth with type 1 diabetes: the SEARCH CVD study

AIM

This study explored the role of glycemic control on cardiac autonomic function, measured by heart rate variability (HRV), in youth with type 1 diabetes.

PATIENTS AND METHODS

A retrospective cohort of 345 youth with type 1 diabetes (mean age, 18.5 years; duration, 10 years) participating in the SEARCH for Diabetes in Youth study were enrolled in the ancillary SEARCH Cardiovascular Disease (CVD) study. Anthropometric, metabolic, and HRV parameters were collected at the current research visit. Glycemic control over time was assessed by the mean glycated hemoglobin (A1c) levels collected over the past 6 years. Multiple linear regression analysis assessed the association between A1c over time and HRV parameters, independent of demographic and CVD risk factors. Participants were categorized into four glycemic control categories based on their mean A1c over time: Group 1, optimal (mean A1c, ≤7.4%); Group 2 (mean A1c, 7.5-8.4%); Group 3 (mean A1c, 8.5-9.4%), and Group 4, poor (mean A1c, ≥9.5%), and a linear trend was explored across these categories.

RESULTS

For every 1% increase in the average A1c over 6 years there was a 5% decrease in the SD of the normal RR interval (SDNN) (P=0.02) and 7% decrease in the root mean square successive difference of the RR interval (RMSSD) (P=0.02), independent of demographic and traditional CVD risk factors. A dose-response relationship between worsening glucose control categories and measures of overall reduced HRV was found.

CONCLUSIONS

Chronic hyperglycemia is the main determinant of early cardiac autonomic dysfunction, manifested as reduced overall HRV and parasympathetic loss, among youth with type 1 diabetes.

Albuminuria according to status of autoimmunity and insulin sensitivity among youth with type 1 and type 2 diabetes

OBJECTIVE

To evaluate whether etiologic diabetes type is associated with the degree of albuminuria in children with diabetes. RESEARCH DESIGN AND METHODS SEARCH: is an observational, longitudinal study of children with diabetes. Youth with newly diagnosed diabetes were classified according to diabetes autoantibody (DAA) status and presence of insulin resistance. We defined insulin resistance as an insulin sensitivity score <25th percentile for the United States general youth population. DAA status was based on positivity for the 65-kD isoform of glutamate decarboxylase and insulinoma-associated protein 2 antigens. The four etiologic diabetes type groups were as follows: DAA(+)/insulin-sensitive (IS) (n = 1,351); DAA(+)/insulin-resistant (IR) (n = 438); DAA(-)/IR (n = 379); and DAA(-)/IS (n = 233). Urinary albumin:creatinine ratio (UACR) was measured from a random urine specimen. Multivariable regression analyses assessed the independent relationship between the four diabetes type groups and magnitude of UACR.

RESULTS

Adjusted UACR means across the four groups were as follows: DAA(+)/IS = 154 μg/mg; DAA(+)/IR = 137 μg/mg; DAA(-)/IR = 257 μg/mg; and DAA(-)/IS = 131 μg/mg (P < 0.005). Only DAA(-)/IR was significantly different. We performed post hoc multivariable regression analysis restricted to the two IR groups to explore the contribution of DAA status and insulin sensitivity (continuous) to the difference in UACR between the IR groups. Only insulin sensitivity was significantly associated with UACR (β = -0.54; P < 0.0001).

CONCLUSIONS

In youth with diabetes, the DAA(-)/IR group had a greater UACR than all other groups, possibly because of the greater magnitude of insulin resistance. Further exploration of the relationships between severity of insulin resistance, autoimmunity, and albuminuria in youth with diabetes is warranted.

Family involvement with the diabetes regimen in young people: the role of adolescent depressive symptoms

AIMS

In young people with Type 1 diabetes, depressive symptoms and shared responsibility for management of diabetes impact upon diabetes management and control. However, the simultaneous effects of both depressive symptoms and parental involvement on diabetes self-care and glycaemic control have not been examined. Thus, the aim of the current study was to examine the relationships between parental involvement and adolescent depressive symptoms in predicting blood glucose monitoring and glycaemic control.

METHODS

One hundred and fifty young people with Type 1 diabetes (mean age 15.3 years) and their parents completed responsibility sharing and depressive symptom assessments, meter assessment of blood glucose monitoring and HbA(1c) at baseline and then 6, 12 and 18 months.

RESULTS

Parental involvement affected HbA1c through blood glucose monitoring only at low levels of adolescent depressive symptoms (score ≤ 6), which made up only 20% of the sample. In the presence of more depressive symptoms, parental involvement no longer was related to HbA1c through blood glucose monitoring. This was the relationship in the majority of the sample (80%).

CONCLUSIONS

While most young people in this sample are not showing evidence of high levels of depressive symptoms, even modest levels of distress interfere with parental involvement in diabetes management. By addressing adolescent depressive symptoms, interventions promoting parental involvement in these families may be more effective.

Glucose control predicts 2-year change in lipid profile in youth with type 1 diabetes

OBJECTIVE

To test the hypothesis that a change in glycated hemoglobin (A1c) over a follow-up interval of approximately 2 years would be associated with concomitant changes in fasting lipids in individuals with type 1 diabetes (T1D).

STUDY DESIGN

All subjects with T1D diagnosed in 2002-2005 in the SEARCH for Diabetes in Youth study with at least 2 study visits ∼12 and ∼24 months after an initial visit were included (age at initial visit, 10.6 ± 4.1 years; 48% female; diabetes duration, 10 ± 7 months; 76% non-Hispanic white; A1c = 7.7% ± 1.4%). Longitudinal mixed models were fit to examine the relationship between change in A1c and change in lipid levels (total cholesterol [TC], high-density lipoprotein-cholesterol [HDL-c], low-density lipoprotein-cholesterol [LDL-c], log triglycerides [TG], and non-HDL-c) with adjustment for possible confounders.

RESULTS

Change in A1c over time was significantly associated with changes in TC, HDL-c, LDL-c, TG, and non-HDL-c over the range of A1c values. For example, for a person with an A1c of 10% and then a 2% decrease in A1c 2 years later (to 8%), the model predicted concomitant changes in TC (-0.29 mmol/L, -11.4 mg/dL), HDL-c (0.03 mmol/L, 1.3 mg/dL), LDL-c (-0.23 mmol/L, -9.0 mg/dL), and non-HDL-c (-0.32 mmol/L, -12.4 mg/dL) and an 8.5% decrease in TG (mmol/L).

CONCLUSIONS

Improved glucose control over a 2-year follow-up was associated with a more favorable lipid profile but may be insufficient to normalize lipids in dyslipidemic T1D youth needing to decrease lipids to goal.

Clinical evolution of beta cell function in youth with diabetes: the SEARCH for Diabetes in Youth study

AIMS/HYPOTHESIS

Few studies have explored the epidemiology of beta cell loss in youth with diabetes. This report describes the evolution and major determinants of beta cell function, assessed by fasting C-peptide (FCP), in the SEARCH for Diabetes in Youth study.

METHODS

Participants were 1,277 youth with diabetes (948 positive for diabetes autoantibodies [DAs] and 329 negative for DAs), diagnosed when aged <20 years, who were followed from a median of 8 months post diagnosis, for approximately 30 months. We modelled the relationship between rate of change in log FCP and determinants of interest using repeated measures general linear models.

RESULTS

Among DA-positive youth, there was a progressive decline in beta cell function of 4% per month, independent of demographics (age, sex, race/ethnicity), genetic susceptibility to autoimmunity (HLA risk), HbA(1c) and BMI z score, or presence of insulin resistance. Among DA-negative youth, there was marked heterogeneity in beta cell loss, reflecting an aetiologically mixed group. This group likely includes youths with undetected autoimmunity (whose decline is similar to that of DA-positive youth) and youth with non-autoimmune, insulin-resistant diabetes, with limited decline (~0.7% per month).

CONCLUSIONS/INTERPRETATION

SEARCH provides unique estimates of beta cell function decline in a large sample of youth with diabetes, indicating that autoimmunity is the major contributor. These data contribute to a better understanding of clinical evolution of beta cell function in youth with diabetes, provide strong support for the aetiological classification of diabetes type and may inform tertiary prevention efforts targeted at high-risk groups.

Insulin resistance and arterial stiffness in healthy adolescents and young adults

AIMS/HYPOTHESIS

Increased arterial stiffness is a risk factor for adverse cardiovascular events in adults with obesity-related insulin resistance (IR) or type 2 diabetes mellitus. Adolescents with type 2 diabetes have stiffer vessels. Whether stiffness is increased in obesity/IR in youth is not known. We sought to determine if IR was a determinant of arterial stiffness in youth, independent of obesity and cardiovascular risk factors.

METHODS

We measured cardiovascular risk factors, IR, adipocytokines and arterial stiffness (brachial artery distensibility [BrachD], pulse wave velocity [PWV]) and wave reflection (augmentation index [AIx]) in 343 adolescents and young adults without type 2 diabetes (15-28 years old, 47% male, 48% non-white). Individuals <85th percentile of BMI were classified as lean (n = 232). Obese individuals were grouped by HOMA index as not insulin resistant (n = 46) or insulin resistant (n = 65) by the 90th percentile for HOMA for lean. Mean differences were evaluated by ANOVA. Multivariate models evaluated whether HOMA was an independent determinant of arterial stiffness.

RESULTS

Risk factors deteriorated from lean to obese to obese/insulin resistant (all p ≤ 0.017). Higher AIx, lower BrachD and higher PWV indicated increased arterial stiffness in obese and obese/insulin-resistant participants. HOMA was not an independent determinant. Age, sex, BMI and BP were the most consistent determinants, with HDL-cholesterol playing a role for BrachD and leptin for PWV (AIx R²= 0.34; BrachD R² = 0.37; PWV R² = 0.40; all p ≤ 0.02).

CONCLUSIONS/INTERPRETATION

Although IR is associated with increased arterial stiffness, traditional cardiovascular risk factors, especially obesity and BP, are the major determinants of arterial stiffness in healthy young people.

The effects of obesity and type 2 diabetes mellitus on cardiac structure and function in adolescents and young adults

AIMS/HYPOTHESIS

We sought to evaluate the effects of obesity and obesity-related type 2 diabetes mellitus on cardiac geometry (remodelling) and systolic and diastolic function in adolescents and young adults.

METHODS

Cardiac structure and function were compared by echocardiography in participants who were lean, obese or obese with type 2 diabetes (obese diabetic), in a cross sectional study. Group differences were assessed using ANOVA. Independent determinants of cardiac outcome measures were evaluated with general linear models.

RESULTS

Adolescents with obesity and obesity-related type 2 diabetes were found to have abnormal cardiac geometry compared with lean controls (16% and 20% vs <1%, p < 0.05). These two groups also had increased systolic function. Diastolic function decreased from the lean to obese to obese diabetic groups with the lowest diastolic function observed in the obese diabetic group (p < 0.05). Regression analysis showed that group, BMI z score (BMIz), group × BMIz interaction and systolic BP z score (BPz) were significant determinants of cardiac structure, while group, BMIz, systolic BPz, age and fasting glucose were significant determinants of the diastolic function (all p < 0.05).

CONCLUSIONS/INTERPRETATION

Adolescents with obesity and obesity-related type 2 diabetes demonstrate changes in cardiac geometry consistent with cardiac remodelling. These two groups also demonstrate decreased diastolic function compared with lean controls, with the greatest decrease observed in those with type 2 diabetes. Adults with diastolic dysfunction are known to be at increased risk of progressing to heart failure. Therefore, our findings suggest that adolescents with obesity-related type 2 diabetes may be at increased risk of progressing to early heart failure compared with their obese and lean counterparts.

Association testing of TCF7L2 polymorphisms with type 2 diabetes in multi-ethnic youth

AIM/HYPOTHESIS

Common variants in the transcription factor 7-like 2 (TCF7L2) gene have been associated with type 2 diabetes in adults. However, it is not known whether TCF7L2 variation increases the risk of early onset type 2 diabetes. Using a case-control design, we examined whether the reported variants [rs12255372 (T/G) and rs7903146 (T/C)] are associated with type 2 diabetes in SEARCH for Diabetes in Youth study participants.

METHODS

Variants were genotyped in 694 non-Hispanic white (NHW) youth (86 cases, mean age 15.5 years, mean BMI 34.8; and 608 controls, mean age 14.4 years, mean BMI 22.3) and 545 African-American (AA) youth (154 cases, mean age 15.9, mean BMI 37; and 391 controls, mean age 14.8, mean BMI 23.8). Logistic regression adjusted for age, sex, BMI and West African ancestry.

RESULTS

The association of the risk T allele with case/control status was different in AA and NHW youth (p = 0.025). Among AA youth, each copy of the T allele (rs7903146) was associated with a 1.97-fold (1.37, 2.82) increased odds for type 2 diabetes (p < 0.0001), after adjustment for age, sex, BMI and African ancestry. No significant association was detected in NHW youth (adjusted OR, 1.14; 0.73, 1.79).

CONCLUSION/INTERPRETATION

TCF7L2 variation is associated with an increased risk of early-onset type 2 diabetes among AA youth, and the association appears to be stronger in AA than NHW youth. This suggests potential different contributions of genetic and environmental factors to early-onset type 2 diabetes by race.

Gender differences in the relationships among obesity, adiponectin and brachial artery distensibility in adolescents and young adults

BACKGROUND

Obesity-related cardiovascular diseases (CVDs) are a major cause of cardiovascular (CV) mortality. Obesity-related reduction in vascular protective adipose-derived proteins, such as adiponectin (APN), has an important role.

METHODS

We compared brachial artery distensibility (BrachD) with APN, the level of adiposity and other CV risk factors (CVRFs) in 431 post-pubertal subjects (mean 17.9 years). Gender differences in average values were examined by t-tests. Correlations among BrachD, obesity and other CVRFs were examined. Regression analysis was performed to determine whether APN provided an independent contribution to BrachD, while controlling for obesity and other CVRFs.

RESULTS

Male subjects had lower BrachD (5.72+/-1.37 vs 6.45+/-1.60% change per mm Hg, P<0.0001) and lower APN (10.50+/-4.65 vs 13.20+/-6.53; all P<0.04) than female subjects. BrachD correlated with APN (r=0.25, P< 0.0001). Both BrachD and APN correlated with measures of body size, including height, weight and body mass index (BMI). Both correlated with higher systolic blood pressure, glucose, insulin and lower high-density lipoprotein cholesterol (all P<0.01). In multivariate analysis, APN, gender, APN*gender and BMI z-score predicted BrachD (r(2)=0.305). On the basis of gender difference, only BMI z-score was significant for male subjects (r(2)=0.080), whereas APN and BMI z-score contributed for female subjects (r(2)=0.242, all P<0.0001).

CONCLUSIONS

BrachD is independently influenced by obesity in both male and female subjects. In female subjects, APN exerts an additional independent effect even after adjusting for blood pressure (BP), lipid levels and insulin. Differences in the effect of the APN-adiposity relationship on obesity-related vascular disease may be one reason for gender differences in the development and progression of atherosclerosis.

Testing the accelerator hypothesis: body size, beta-cell function, and age at onset of type 1 (autoimmune) diabetes

OBJECTIVE

The "accelerator hypothesis" predicts that fatness is associated with an earlier age at onset of type 1 diabetes. We tested the hypothesis using data from the SEARCH for Diabetes in Youth study.

RESEARCH DESIGN AND METHODS

Subjects were 449 youth aged <20 years at diagnosis who had positive results for diabetes antibodies measured 3-12 months after diagnosis (mean 7.6 months). The relationships between age at diagnosis and fatness were examined using BMI as measured at the SEARCH visit and reported birth weight, both expressed as SD scores (SDSs).

RESULTS

Univariately, BMI SDS was not related to age at diagnosis. In multiple linear regression, adjusted for potential confounders, a significant interaction was found between BMI SDS and fasting C-peptide (FCP) on onset age (P < 0.0001). This interaction remained unchanged after additionally controlling for number and titers of diabetes antibodies. An inverse association between BMI and age at diagnosis was present only among subjects with FCP levels below the median (<0.5 ng/ml) (regression coefficient -7.9, P = 0.003). A decrease of 1 SDS in birth weight (639 g) was also associated with an approximately 5-month earlier age at diagnosis (P = 0.008), independent of sex, race/ethnicity, current BMI, FCP, and number of diabetes antibodies.

CONCLUSIONS

Increasing BMI is associated with younger age at diagnosis of type 1 diabetes only among those U.S. youth with reduced beta-cell function. The intrauterine environment may also be an important determinant of age at onset of type 1 diabetes.

Backache in gynaecologists

The objectives of the study were to assess the overall prevalence of backache in gynaecologists and determine its impact on work, and to identify possible occupational risk factors. The sample comprised gynaecologists, both active and retired, listed as members of the Ulster Obstetrical and Gynaecological Society, who were asked to complete and return a postal questionnaire. The response rate was 94% (107/114). The prevalence of backache, which included pain arising in the thoracic and lumbosacral regions, was 72%. Fifty-three per cent of those with back pain blamed it on working in obstetrics and gynaecology. Overall, 32% of gynaecologists required a change of their work practice, 20% had taken time off work and 8% had required surgery. We conclude that significant morbidity results from backache in gynaecologists. This has economic implications and requires further assessment to improve prevention, with emphasis on individual training and ergonomic evaluation of work-related postures.

First-phase insulin release during the intravenous glucose tolerance test as a risk factor for type 1 diabetes

OBJECTIVE

To determine the relationship between first-phase (1 minute + 3 minutes) insulin production during the intravenous glucose tolerance test (IV-GTT) and risk factors for developing type 1 diabetes.

STUDY DESIGN

Relatives of persons with type 1 diabetes (n = 59,600) were screened for islet cell antibodies (ICAs). Subjects who had positive screening results underwent IV-GTT (> or =2 times), repeat ICA screening, insulin autoantibody (IAA) screening twice, and an oral glucose tolerance test.

RESULTS

Of the 59,600 subjects in the study, 2199 (3.69%) had positive findings on initial ICA test. IV-GTTs were performed in 1622 subjects, with children <8 years having the lowest first-phase insulin release (FPIR) and subjects 8 to 20 years of age having the highest FPIR. The FPIR was lower for subjects with a confirmed positive ICA test result or a positive IAA test result, subjects with higher titers of ICA or IAA, and subjects who had an abnormal (impaired or diabetic) oral glucose tolerance test result.

CONCLUSION

FPIR in the IV-GTT correlates strongly with risk factors for development of type 1 diabetes.

The levonorgestrel intra-uterine system: therapeutic application in family planning

OBJECTIVE

To assess the non-contraceptive benefits of the levonorgestrel intra-uterine system 12 months following insertion in a family planning setting.

DESIGN

Postal questionnaire survey.

SETTING

Family planning clinics at the Ulster and Bangor Hospitals.

SUBJECTS

Eighty-six consecutive subjects fitted with the levonorgestrel intra-uterine system.

RESULTS

Response rate 87.3%. Outcome measured in terms of compliance, satisfaction and menstrual symptomatology. Reasons for insertion were as follows: 21.7% contraception only; 65.2% menorrhagia, 24.6% dysmenorrhoea and 1.4% premenstrual syndrome. Duration of menses was 8.25 days pre-insertion and 2.41 days at 12 months. Of the subjects, 59.4% experienced at least one hormonal side effect; 10.1% of systems were removed within 12 months. At 12 months 86.9% of women were satisfied and 9.8% of women planned to discontinue.

CONCLUSION

The levonorgestrel intra-uterine system was acceptable to almost 80% of women after 12 months, with significant reduction in duration of menses. Family planning clinics are an ideal setting to implement the guidelines for the initial management of menorrhagia.

The type 2 family: a setting for development and treatment of adolescent type 2 diabetes mellitus

OBJECTIVE

To identify physical, behavioral, and environmental features of adolescents (aged 11-17 years) with type 2 diabetes mellitus and their families to define the involvement of known risk factors and to define a profile of at-risk individuals.

DESIGN AND METHODS

A total of 42 subjects from 11 families with an adolescent in whom type 2 diabetes was previously diagnosed participated. All subjects underwent anthropometric measurement and completed food frequency and eating disorder questionnaires, and were classified according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. In addition, laboratory tests to determine levels of hemoglobin A1c, fasting glucose, C peptide, insulin, and proinsulin were performed.

RESULTS

Type 2 diabetes had been diagnosed in 5 of 11 mothers and 4 of 11 fathers before the study. Type 2 diabetes was diagnosed in 3 of the remaining 7 fathers during the study. In 3 families, both parents were affected with type 2 diabetes. As a group, participants were obese, with a body mass index higher than the 95th percentile for probands and fathers, and higher than the 85th percentile for mothers and siblings. The sum of skin fold measurements was above the 95th percentile for the probands, their siblings, and the parents. All groups had high fat intake and low fiber intake. None of the subjects participated in a structured or routine exercise program, and most reported no regular physical activity. Three of the probands met the criteria for binge-eating disorder, and 6 additional patients had notable characteristics of the disorder. Mothers affected with type 2 diabetes had markedly abnormal hemoglobin A1c levels, indicating poor control. There were no group differences in fasting concentrations of insulin, proinsulin, or C peptide. However, a third of the mothers with type 2 diabetes, and all but 1 of the siblings, had evidence of insulin resistance.

CONCLUSIONS

Adolescents in whom type 2 diabetes has been diagnosed, as well as their first-degree family members, are obese. In addition, the incidence of diagnosed and undiagnosed type 2 diabetes or of insulin resistance in the families of adolescents with type 2 diabetes is striking. Probands and other family members have lifestyles characterized by high fat intake, minimal physical activity, and a high incidence of binge eating. These findings indicate that the families of adolescents with type 2 diabetes share many anthropometric and lifestyle risk factors. The design of treatment programs for adolescents with type 2 diabetes will need to address the lifestyle and health habits of the entire family.

Urinary incontinence in Northern Ireland: a prevalence study

OBJECTIVE

To determine the prevalence of urinary incontinence in a Northern Ireland community drawn from four neighbouring geographical areas and to assess factors predisposing to the development of urinary incontinence.

SUBJECTS AND METHODS

A three-page self-administered postal questionnaire was sent to 1050 women (age range 35-74 years), recruited randomly from a target population of 43 829 women. The main survey was preceded by a pilot survey. Respondents and those not responding were compared.

RESULTS

The overall response rate was 65.6% (689/1050); there was no significant difference between respondents and those not responding. Two-hundred and thirty-one women (33.5%) reported incontinence 'sometimes' and 161 (23.4%) 'often'. Of those who had urinary incontinence, sanitary protection was required by 21.7% (85/392). This equates to 12.3% (85) of the total study population. Age (chi2=20.34; P<0.001) and parity (Mann-Whitney U-test, P< 0.001) were associated with urinary incontinence, with a higher proportion of women aged 45-54 years having urinary incontinence. The menopause and postnatal pelvic floor exercises were not associated with urinary incontinence. Overall 19.9% (78/392) of women with urinary incontinence had consulted their general practitioner. Of those who required sanitary protection, 40% (34/85) had consulted their doctor.

CONCLUSION

Urinary incontinence is common; it is sufficiently severe to require sanitary protection in 12% of women aged 35-74 years in a Northern Ireland community.

Nocturnal blood pressure in young patients with insulin-dependent diabetes mellitus: correlation with cardiac function

Lack of a decline in nocturnal blood pressure is associated with an adverse effect on end organs in adults with insulin-dependent diabetes mellitus (IDDM). The role of the decline in nocturnal blood pressure in young patients with IDDM is not known. We studied 25 white subjects with IDDM (age = 20.8 +/- 3.7 years, mean +/- SD), 8 of whom were female. The duration of IDDM in these subjects was 12.9 +/- 5.4 years (mean +/- SD). We determined the values for glycosylated hemoglobin (HgbA1), 24-hour ambulatory blood pressure, diastolic cardiac function (the ratio of peak E wave to peak A wave velocity (E/A) and indexed peak filling rate ¿PFR/SV¿ by Doppler echocardiography), and albumin excretion rate. The HgbA1 level was 10.9% +/- 1.9% (mean +/- SD; normal range = 4.5%-8.5%). The HgbA1 concentration was inversely correlated (p < 0.005) with the decline in systolic (r = 0.57) and diastolic (r = -0.55) nocturnal blood pressure. Diastolic cardiac dysfunction ¿E/A ratio [r = 0.42, p < 0.03) and PFR/SV (r = 0.52, p < 0.01)¿ correlated with a smaller decrease in nocturnal diastolic blood pressure. An inverse correlation between decline in nocturnal systolic blood pressure and log albumin excretion rate (r = -0.37, p = 0.07) approached statistical significance. We conclude that poor glycemic control adversely affects nocturnal blood pressure and that the latter may play an important role in cardiac and possibly renal dysfunction in early IDDM.

Diastolic dysfunction in young patients with insulin-dependent diabetes mellitus as determined by automated border detection

Diastolic dysfunction is an early harbinger for systolic dysfunction in insulin-dependent diabetes mellitus (IDDM). To determine the role of automated border detection (ABD) in detecting diastolic abnormalities and whether IDDM control correlates with abnormalities, 21 young IDDM patients (22 +/- 4 years old) and 19 control subjects underwent echocardiography. ABD indices included the percent contribution to total left ventricular filling of the three phases of diastole (rapid filling, diastasis, and atrial contraction) and peak filling rate. Doppler indices included E/A ratio and peak filling rate. Rapid filling phase was lower in the IDDM patients compared with control subjects (73% +/- 5% versus 80% +/- 5%, p = 0.0006), and atrial contraction filling was higher (19% +/- 4% versus 14% +/- 3%, p = 0.0003). Doppler indexes showed similar changes. Glycosylated hemoglobin, insulin dosage, and duration of IDDM since puberty were associated with filling abnormalities. Young patients with IDDM have increased atrial contraction and reduced rapid filling phases detected by automatic border detection, and these diastolic abnormalities are related to the diabetic disease process.

Diabetic ketoacidosis among obese African-American adolescents with NIDDM

OBJECTIVE

To determine whether ketosis at the time of presentation occurs among African-American adolescents with NIDDM.

RESEARCH DESIGN AND METHODS

We reviewed the charts of all islet cell antibody (ICA) negative patients diagnosed with NIDDM at Children's Hospital Medical Center (CHMC) between 1982 and 1995.

RESULTS

Between 1982 and 1985, 70 adolescents were diagnosed with NIDDM. Of these, ICA determinations were available and negative on 42 subjects (28 African-American, 12 white). Twelve of 28 (42%) African-American patients presented with ketonuria, and seven of 28 (25%) presented with DKA. In comparison, none of the 12 white adolescents with NIDDM had ketonuria at presentation or during their subsequent course. Mean follow-up time for patients with ketosis at presentation was 24 months. There was no difference between the age, BMI, or sex distribution of patients with and without ketosis. Previously diagnosed hypertension was present in 42% of patients presenting with ketosis, compared with 17% of the general NIDDM population at CHMC.

CONCLUSIONS

We conclude that ketosis may occur among African-American adolescents with NIDDM, as has been previously reported among African-American adults with NIDDM. Therefore, ketosis in obese young African-American patients with new-onset diabetes does not necessarily imply the presence of IDDM and insulin dependence.

6-Hydroxymelatonin sulfate excretion in human puberty

We investigated the relationship of urinary excretion rate of 6-hydroxymelatonin sulfate (SM), the main metabolite of melatonin, with pubertal development and determined the day to day variability of SM excretion. Healthy subjects 4-31 years old completed one or multiple timed overnight urine collections. SM excretion rate per body size was significantly higher in 99 prepubertal subjects (35.5 +/- 2.3 ng/h/kg and 0.97 +/- 0.06 microgram/hr/m2) than in 86 pubertal subjects (18.1 +/- 1.1 ng/hr/kg and 0.61 +/- 0.03 microgram/hr/m2) or in 29 adults (15.0 +/- 1.5 ng/hr/kg and 0.59 +/- 0.06 microgram/hr/m2); no significant difference was present in pubertal stages 2 to 5. Among the prepubertal children, SM excretion rate in mid childhood was significantly higher than in late childhood. The variability of SM and creatinine excretion examined in 52 children, adolescents and adults with three or four collections was defined as the mean of the 52 coefficients of variation for the multiple measures in each subject. The variability of total nocturnal SM (25.9 +/- 2.6%) was similar to that of total creatinine (21.7 +/- 2.3%) and neither was significantly correlated with the variability in start time or duration of urine collection. The results suggest that, relative to body size, melatonin secretion rate is higher in mid childhood, decreases during late childhood, and remains stable from pubertal stage 2 to adulthood. The decline in melatonin secretion rate occurs during the developmental phase of disinhibition of the gonadotropin releasing hormone pulse generator. Hence, we infer that melatonin may be a suppressive factor of puberty during childhood. The substantial individual variability observed for SM excretion calls for caution in using single urine collections in longitudinal studies or in studies of drug responses.

Increased incidence of non-insulin-dependent diabetes mellitus among adolescents

OBJECTIVE

To determine whether a rise in the diagnosis of non-insulin- dependent diabetes mellitus (NIDDM) has accompanied the rise in obesity in the pediatric population, as it has among adults.

STUDY DESIGN

Medical records of 1027 consecutive patients from birth to age 19 years with a diagnosis of diabetes from 1982 to 1995 at a regional, university-affiliated pediatric diabetes referral center were reviewed and classified according to criteria of the National Diabetes Data Group.

RESULTS

The number of patients with a diagnosis of NIDDM rose from approximately 4% of new diagnoses of diabetes in patients from birth to age 19 years before 1992, to 16% in 1994. Among patients 10 to 19 years of age, NIDDM accounted for 33% of diagnoses of diabetes in 1994. The incidence of adolescent NIDDM in Greater Cincinnati increased tenfold, from 0.7/100,000 per year in 1982 to 7.2/100,000 per year in 1994. The mean (+/- SD) age and body mass index at presentation were 13.8 +/- 1.9 years and 37.7 +/- 9.6 kg/m2, respectively. The overall female/male ratio was 1.7:1, and female patients were seen 1 year earlier than male patients (p < 0.01). Male subjects had a higher body mass index than female subjects (p < 0.05). A first-degree relative with NIDDM was identified for 65% of patients. At presentation, 21% of the patients had had a diagnosis of at least one other condition associated with obesity.

CONCLUSION

There is an increasing incidence of NIDDM among adolescents in Greater Cincinnati, accompanying the national rise in adolescent obesity. Obesity and strong family histories of NIDDM are important risk factors. Because NIDDM leads to long-term morbidity, the prevention of obesity as well as early identification of overt disease, is critical.

Absence of molecular defect in the type II 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) gene in premature pubarche children and hirsute female patients with moderately decreased adrenal 3 beta-HSD activity

To date the molecular basis and hormonal criteria for inherited mild late-onset 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency congenital adrenal hyperplasia (CAH) have not been defined. We have thus investigated the presence or absence of mutation in the type II 3 beta-HSD gene encoding adrenal/gonadal 3 beta-HSD in each of five premature pubarche children and hirsute female patients manifesting moderately decreased adrenal 3 beta-HSD activity. ACTH-stimulated hormonal levels in all patients compared with mean levels in pubertal stage-matched normal subjects were between 2.5 and 6.5 SD for 17-hydroxypregnenolone levels, and between 2.5 and 7 SD for dehydroepiandrosterone levels in all except one patient. 17-Hydroxypregnenolone to cortisol ratios were between 2.5 and 4.3 SD, and dehydroepiandrosterone to androstenedione ratios were between 3 and 8.6 SD. The type II 3 beta-HSD gene regions of a putative promoter, exons I, II, III, and IV, and exon-intron boundaries in all subjects were amplified by polymerase chain reaction and then sequenced. All patients had normal sequences of the type II 3 beta-HSD gene in both alleles. Three female patients heterozygotic for severe 3 beta-HSD deficiency CAH with one allele mutation of the gene demonstrated normal ACTH-stimulated hormone profiles. These data indicate that moderately decreased adrenal 3 beta-HSD activity resulting in modestly increased delta 5 precursor steroid levels and delta 5 to delta 4 steroid ratios in premature pubarche and hirsute patients is not caused by a mutation in the type II 3 beta-HSD gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular status in young patients with insulin-dependent diabetes mellitus

BACKGROUND

Although the existence of diabetic cardiomyopathy in adults is firmly established, the presence of cardiac abnormalities in young diabetic patients is not universally accepted. We sought to determine the early stages of cardiac derangement and whether they are associated with renal dysfunction.

METHODS AND RESULTS

Thirty-nine patients (29 boys; mean age, 17.6 +/- 3.4 years) with insulin-dependent diabetes mellitus underwent echocardiography and timed overnight urine collection. Echocardiographic evaluation consisted of left ventricular mass, performance (shortening fraction, velocity of circumferential fiber shortening, stroke volume, and cardiac index), preload (end-diastolic dimension and volume), after-load (end-systolic wall stress and systemic vascular resistance), and contractility (velocity of fiber shortening relative to wall stress). Creatinine clearance and albumin excretion were measured from the urine sample. Glycosylated hemoglobin levels were measured; height and weight were measured; and Quetelet index (weight/height2) was calculated. These data were compared with control data. Left ventricular mass (26 +/- 6 versus 22 +/- 6 g/ht2.7, P < .01), the indexes of performance, blood pressure, and contractility (0.14 +/- 0.14 versus 0.003 +/- 0.03 circumference/s, P < .0003) were significantly higher in the diabetic patients than in control subjects. To evaluate the correlates of left ventricular mass and contractility in the diabetic patients, univariate and multiple regression analyses were performed. Significant univariate correlations of mass included albumin excretion (r = .36, P < .02), glycosylated hemoglobin (r = .35, P < .04), and stroke volume (r = .34, P < .03). A multivariate model included Quetelet index, albumin excretion, and duration of diabetes. Significant univariate correlations of contractility included insulin dosage (r = -.36, P < .02), creatinine clearance (r = .40, P < .02), and Quetelet index (r = .34, P < .03). A multivariate model included insulin dosage and creatinine clearance.

CONCLUSIONS

Early onset of diabetes mellitus is associated with increased left ventricular mass, performance, contractility, and blood pressure. These cardiovascular findings are correlated with increased creatinine clearance and microalbuminuria. These relations suggest that alterations in cardiovascular and renal function may occur in parallel in adolescents with insulin-dependent diabetes mellitus.

Genotoxicity and carcinogenicity in rats and mice of 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7- one: an intestinal bacterial metabolite of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline

BACKGROUND

Compounds formed on the surface of fried or grilled meat and fish may be associated with increased risk of colon cancer. Normal intestinal bacteria can convert one of these compounds, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), to the 7-hydroxy metabolite, 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7-o ne (7-OHIQ), a direct-acting mutagen.

PURPOSE

We studied the genotoxicity and carcinogenicity of 7-OHIQ to determine if it is responsible for the colon-specific activity of IQ.

METHODS

The effects of pure, synthetic 7-OHIQ on DNA were evaluated in the Ames Salmonella typhimurium TA98 test, with and without an induced rat liver S9 fraction, and in the Williams DNA repair test using freshly explanted rat hepatocytes. 7-OHIQ was also subjected to an in vivo bioassay for 21 months by long-term intrarectal infusion in male F344 rats, using IQ and N-nitrosomethylurea (NMU) given intrarectally as positive tumor-producing controls. The standard NIH-07 rodent diet was supplemented with 15% corn oil to maximize any effect of the infused materials on the colon. A parallel bioassay involved intraperitoneal injection of 7-OHIQ in newborn mice, followed by dietary administration from week 11 to week 67. Again, IQ and NMU were used as positive controls.

RESULTS

We confirmed that 7-OHIQ is a direct-acting mutagen in the Ames test, with added S9 liver fraction giving higher mutagenicity. 7-OHIQ was negative in the Williams test, whereas IQ was positive. 7-OHIQ did not induce colon cancer in rats, and in the newborn mouse test it produced only a low incidence of liver neoplasms.

CONCLUSIONS

7-OHIQ is not genotoxic, for to be so classified it must be definitely positive in both the Ames and Williams tests; moreover, it is not carcinogenic, in marked contrast to IQ and NMU.

Distribution and correlates of creatinine clearance in children and adolescents with blood pressure elevation

The kidney has been implicated as both an etiologic factor and as a target organ in patients with essential hypertension. Renal function has not been studied extensively in children and adolescents with essential hypertension. Eighty-eight subjects, aged 6 to 23 years, with blood pressure persistently above the 90th percentile for age were studied. Creatinine clearance was determined from a single 24-hour urine collection. The mean creatinine clearance was 129.3 +/- 55.3 ml/min per 1.73 m2. Multiple regression analysis was used to investigate potential correlates of creatinine clearance. Because creatinine clearance was not normally distributed, the logarithm of creatinine clearance was used as the dependent variable. Body mass index, resting heart rate, and basal supine plasma renin activity were significant direct independent correlates. Peripheral vascular resistance at maximal exercise was an inverse correlate of the logarithm of creatinine clearance. These findings are consistent with previous studies of adults and may provide the basis for strategies to identify young patients with essential hypertension who are at risk for the development of renal dysfunction.

Maternal side effects of prenatal dexamethasone therapy for fetal congenital adrenal hyperplasia

Prenatal treatment of virilizing congenital adrenal hyperplasia in female fetuses via maternal dexamethasone (Dex) therapy (1-1.5 mg/day) from first trimester to birth was associated with excessive weight gain (47-56 pounds at 35-37 weeks gestation), Cushingoid facial features, severe striae resulting in permanent scarring, and hyperglycemic response (8-11.7 nmol/L) to oral glucose administration in all our experience (three cases). Other symptoms included hypertension, gastrointestinal intolerance, or extreme irritability. Previous pregnancies were uncomplicated by these problems. In each case, first or second trimester amniotic fluid 17-hydroxyprogesterone (17OHP, 17-41 nmol/L; normal less than 0.4 nmol/L), androstenedione (22-31 nmol/L, normal less than 5 nmol/L), and testosterone levels (0.54-0.7 nmol/L, normal less than 0.4 nmol/L) during Dex treatment were elevated regardless of the newborn genital outcome. Maternal serum estriol (E3) levels in one mother (normal newborn genitalia) were consistently low (less than 0.2 nmol/L) during the second and third trimester. In two mothers (partially virilized newborn genitalia) initial second trimester E3 levels were unsuppressed (11, 17.4 nmol/L) and suppressed (less than 1.4 nmol/L) following short-term increased dose.

CONCLUSION

prenatal Dex treatment of virilizing congenital adrenal hyperplasia at a dose of 1-1.5 mg daily throughout gestation is associated with significant maternal side effects. Parents should be informed of these side effects before initiation of treatment. Careful monitoring for signs of side effects, medical intervention when necessary, and lowering of Dex dose during the second half of gestation would minimize the side effects. Maternal serum E3 levels appear useful for prediction of fetal outcome while amniotic fluid steroid levels may not.

Profile of Renal Permselectivity by Simultaneous Enzyme-Linked Immunosorbent Assay of Albumin, Transferrin, IgG, and α1-Microglobulin with a New Microplate Reader

A competitive enzyme-linked immunosorbent assay (ELISA) is described for determining a renal permselectivity profile involving the urinary proteins albumin, transferrin, IgG, and alpha 1-microglobulin (alpha 1-m). The ELISA reader uses a computer-controlled array of multiplexed light-emitting diode (LED)-photodiode pairs for rapid measurements of absorbance on microplates. A 3,3'-dimethylnaphthidine reagent adapts the 3,5,3',5'-tetramethylbenzidine chromophore to monochromatic LED emission at 550 nm. We applied this ELISA to the determination of renal permselectivity in healthy children and young adults and in children with insulin-dependent diabetes mellitus. The geometric means (and SD) of protein excretion rates in a group of 85 normal subjects were as follows: albumin, 3.5 micrograms/min (1.83); transferrin, 173 ng/min (2.76); IgG, 1.11 micrograms/min (2.22), and alpha 1-m, 0.98 microgram/min (2.36).

Profile of renal permselectivity by simultaneous enzyme-linked immunosorbent assay of albumin, transferrin, IgG, and alpha 1-microglobulin with a new microplate reader

A competitive enzyme-linked immunosorbent assay (ELISA) is described for determining a renal permselectivity profile involving the urinary proteins albumin, transferrin, IgG, and alpha 1-microglobulin (alpha 1-m). The ELISA reader uses a computer-controlled array of multiplexed light-emitting diode (LED)-photodiode pairs for rapid measurements of absorbance on microplates. A 3,3'-dimethylnaphthidine reagent adapts the 3,5,3',5'-tetramethylbenzidine chromophore to monochromatic LED emission at 550 nm. We applied this ELISA to the determination of renal permselectivity in healthy children and young adults and in children with insulin-dependent diabetes mellitus. The geometric means (and SD) of protein excretion rates in a group of 85 normal subjects were as follows: albumin, 3.5 micrograms/min (1.83); transferrin, 173 ng/min (2.76); IgG, 1.11 micrograms/min (2.22), and alpha 1-m, 0.98 microgram/min (2.36).

Atrial natriuretic factor during the perinatal period: equal depletion in both atria

Data in the literature concerning atrial natriuretic factor (ANF) physiology in the fetus and newborn, although limited, suggest significant activity during the perinatal period. To characterize further ANF physiology during this time, we documented immunoreactive ANF (IR-ANF) concentrations in the right and left atria before and immediately after birth as well as in the hearts of immature and adult rats. There was a significant decrease in the concentration of IR-ANF in both right and left atria on the d before birth that persisted for the first 48 h of life [d 20 fetal right 570 (106, 90), left 580 (86, 75); d 21 fetal right 270 (70, 55), left 214 (117, 75); 1 d right 206 (39, 33), left 229 (41, 35); 2-d right 352 (35, 32), left 237 (26, 23) [geometric mean (upper SE, lower SE) in ng ANF/mg protein]. Repletion of ANF stores began in the right atrium on d 2 of life and in the left atrium between d 2 and 5. The highest levels of IR-ANF were observed at d 15 [d 5 right 1439 (53,51), left 1547 (83,79); d 15 right 2034 (90,86), left 1943 (108, 102); adult right 1380 (119, 109), left 963 (118, 105)]. In contrast to normal adult animals, factors mediating the observed change affect both atria equally during the perinatal period. The concentration of IR-ANF in the right and left atrium of the fetal, newborn, and immature animals was equal. These data document significant alterations in intraatrial IR-ANF concentrations in the perinatal period.(ABSTRACT TRUNCATED AT 250 WORDS)

Hamartoma of the tuber cinereum: a comparison of MR and CT findings in four cases

Hamartoma of the tuber cinereum is a well-recognized cause of central precocious puberty. We report three patients with an isodense, nonenhancing mass within the interpeduncular cistern identified by CT. In a fourth patient, the CT scan was normal. MR imaging was obtained in all cases and demonstrated a sessile or pedunculated mass of the posterior hypothalamus arising from the region of the tuber cinereum. The smallest mass was 2 mm in diameter and was found in the patient in whom the CT scan was normal. The signal intensity of the masses was generally homogeneous and isointense relative to gray matter on T1- and intermediate-weighted images, and hyper-intense on T2-weighted images. MR imaging accurately diagnoses hypothalamic hamartomas, identifies small hamartomas of the tuber cinereum more sensitively than CT does, and provides optimal imaging for serial evaluation while the patient is being treated medically.

Atrial antinatriuretic factor in the developing Dahl hypertensive rat

In order to determine the developmental pattern of atrial concentrations of atrial natriuretic factor (ANF) in the Dahl hypertension-prone rat, atrial ANF concentrations were measured in inbred hypertension-prone (S/JR) and hypertension-resistant (R/JR) Dahl rats at 5, 15, 25, and 51 days of age. In both strains, atrial ANF concentrations peaked at 15 days of age. Atrial ANF concentrations did not differ between the two strains from 5 to 25 days of age. However, by 51 days of age, atrial ANF concentrations in the S/JR rat were significantly greater than those of the R/JR rat. Combining these data with developmental patterns of plasma renin activity in S/JR rats suggests the possibility that the S/JR rat may become intravascularly volume-expanded between 25 and 51 days of age. This volume expansion may contribute to the etiology of hypertension in this model of essential hypertension.

Atrial natriuretic polypeptide in the fetal rat: ontogeny and characterization

The presence of immunoreactive atrial natriuretic polypeptide (ANP) has been demonstrated in fetal atria early in gestation but further definition of fetal ANP has not been reported. To characterize the principal molecular forms of fetal ANP and to compare fetal ANP to that of the adult of the same species, we extracted the atria of pregnant adult and 20-day fetal rats, the hearts of 14-day fetuses, and intact 12-day fetuses in 1 M acetic acid. Tissue collected from littermates was pooled. We measured ANP by radioimmunoassay before and after gel filtration on Sephadex G-75 in each group. ANP concentrations (means +/- 1 SD) in ng/mg protein and ng/animal were 1296 +/- 505 and 7707 +/- 1877 in adult atria (n = 17), 174 +/- 44 and 62 +/- 13 in 20-day fetal atria (n = 7), and 33 +/- 5.3 and 3.7 +/- 0.9 in 14-day fetal hearts (n = 6), respectively. Acid extracts from intact 12-day fetuses did not dilute in parallel to the standard curve; therefore, concentrations of ANP for the 12-day fetuses are not reported. ANP concentration rose from the 20-day fetus to the adult (p less than 0.0001). The major species of ANP eluting from the Sephadex column had an apparent molecular weight of 16 K in all groups. We conclude: 1) ANP is present in the fetus shortly after the completion of organogenesis; 2) 16 K ANP is the principal intracardiac species in the fetus and the adult; and 3) the existence of ANP soon after cardiac development suggests a possible role for ANP in fetal blood pressure and sodium and water homeostasis.

Short-term, high-dose, systemic steroids in children with asthma: the effect on the hypothalamic-pituitary-adrenal axis

Children with chronic asthma frequently receive "bursts" (less than 7 days) of short-term, high-dose prednisone (1 to 2 mg/kg/day) for acute exacerbations of their disease. Certain of these patients may also require inhaled corticosteroids (IC) for control. The effect of these "bursts" on the hypothalamic-pituitary-adrenal axis (HPAA) is unclear. To test the integrity of the HPAA in such patients, we measured plasma cortisol (F) in response to serial administration of insulin-induced hypoglycemia (nadir = 34 +/- 1.2 mg/dl; mean +/- SE), followed by 250 micrograms/1.73 m2 of synthetic ACTH in the following children with asthma: group I, seven patients who received no more than one "burst" per year (0.71 +/- 0.2); group II, six individuals who received more than one "burst" per year (3.6 +/- 0.2) and no IC; and group III, 10 subjects who received more than one "burst" per year (4.7 +/- 0.3) plus IC. All patients received daily theophylline and beta-agonists; seven patients were taking sodium cromolyn. No patients received troleandomycin. Compared to group I (control subjects), 16% of group II had a subnormal response of F to hypoglycemia. In addition, a subnormal response of F to hypoglycemia or ACTH was documented in 20% and 10% of group III, respectively. All individuals with a subnormal response of F to either hypoglycemia or ACTH received four or more "bursts" per year. We conclude that as a group, children affected by asthma treated with "bursts" alone or "bursts" plus IC appear to have a normal HPAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Crossed fused ectopia with a blind left ureter in a young woman with Turner's syndrome: sonographic and radiological demonstration of a previously undescribed variant

A previously undocumented variant of crossed fused ectopia in a young woman with Turner's syndrome is reported, with emphasis on sonographic and radiological techniques for diagnosis and subsequent evaluation.

Idiopathic hyperaldosteronism. A possible role for aldosterone-stimulating factor

To test the hypothesis that idiopathic hyperaldosteronism is secondary to increased adrenal stimulation by aldosterone-stimulating factor, we measured the latter in seven patients with idiopathic hyperaldosteronism and in four patients who had undergone surgical removal of an aldosterone-producing adenoma. In the patients with hyperaldosteronism, plasma aldosterone concentrations (mean +/- 1 S.E.) were 38 +/- 10 and 78 +/- 19 ng per deciliter in the supine and upright position, respectively (P less than 0.01). Supine plasma aldosterone-stimulating factor was 81 +/- 5 ng per deciliter in 15 normal subjects and 185 +/- 10 (P less than 0.01) in the patients with idiopathic hyperaldosteronism. After removal of an aldosterone-producing adenoma, plasma aldosterone-stimulating factor was normal. The supine value in each patient with idiopathic hyperaldosteronism was above the normal range (61 to 91 ng per deciliter) and increased to 290 +/- 59 ng per deciliter after four hours of upright posture. Twenty-four hour urinary excretion of aldosterone-stimulating factor was 424 +/- 35 ng (normal, 145 +/- 3; P less than 0.01) by affinity chromatography and high-pressure liquid chromatography, and it was not suppressed after two days of treatment with dexamethasone (0.5 mg orally every six hours). At the end of 48 hours, plasma concentrations were 248 +/- 40 ng per deciliter. Plasma cortisol and ACTH concentrations were under 2 micrograms per deciliter and under 40 pg per milliliter, respectively. We conclude that increased secretion of aldosterone-stimulating factor may be the cause of idiopathic hyperaldosteronism.

18p - syndrome with a single central maxillary incisor

A child with a single central maxillary incisor and a deletion of the short arm of chromosome 18 (18p—) is presented. He is the first patient in whom this association has been found.