Fast-food habits, weight gain, and insulin resistance (the CARDIA study): 15-year prospective analysis.

BACKGROUND: Fast-food consumption has increased greatly in the USA during the past three decades. However, the effect of fast food on risk of obesity and type 2 diabetes has received little attention. We aimed to investigate the association between reported fast-food habits and changes in bodyweight and insulin resistance over a 15-year period in the USA. METHODS: Participants for the CARDIA study included 3031 young (age 18-30 years in 1985-86) black and white adults who were followed up with repeated dietary assessment. We used multiple linear regression models to investigate the association of frequency of fast-food restaurant visits (fast-food frequency) at baseline and follow-up with 15-year changes in bodyweight and the homoeostasis model (HOMA) for insulin resistance. FINDINGS: Fast-food frequency was lowest for white women (about 1.3 times per week) compared with the other ethnic-sex groups (about twice a week). After adjustment for lifestyle factors, baseline fast-food frequency was directly associated with changes in bodyweight in both black (p=0.0050) and white people (p=0.0013). Change in fast-food frequency over 15 years was directly associated with changes in bodyweight in white individuals (p<0.0001), with a weaker association recorded in black people (p=0.1004). Changes were also directly associated with insulin resistance in both ethnic groups (p=0.0015 in black people, p<0.0001 in white people). By comparison with the average 15-year weight gain in participants with infrequent (less than once a week) fast-food restaurant use at baseline and follow-up (n=203), those with frequent (more than twice a week) visits to fast-food restaurants at baseline and follow-up (n=87) gained an extra 4.5 kg of bodyweight (p=0.0054) and had a two-fold greater increase in insulin resistance (p=0.0083). INTERPRETATION: Fast-food consumption has strong positive associations with weight gain and insulin resistance, suggesting that fast food increases the risk of obesity and type 2 diabetes.

Screening for abnormal glucose tolerance in adolescents with polycystic ovary syndrome.

Insulin resistance is common in adults with polycystic ovary syndrome (PCOS). Although recent data demonstrate that insulin resistance is present in the early stages of PCOS, the prevalence of insulin resistance in adolescents with PCOS has not been determined. Likewise, the prevalence of impaired glucose tolerance (IGT) or type 2 diabetes mellitus (DM) in adolescent cohorts has not been established. In this study we sought to obtain preliminary data regarding the prevalence of IGT and DM in adolescents with PCOS and to assess the ability of screening tests to predict these abnormalities within this population. Twenty-seven adolescents with PCOS underwent oral glucose tolerance tests. Plasma glucose and insulin levels were obtained at baseline, and glucose was measured 2 h after a 75-g glucose challenge. The 2-h plasma glucose level was used to categorize subjects as having IGT or the provisional diagnosis of DM. Eight of our 27 subjects had IGT, and 1 had previously undiagnosed DM. These abnormalities were seen among lean and obese subjects. Fasting plasma glucose levels and simple measures of insulin resistance were suboptimal predictors of IGT and DM within our cohort. As in adults, our results indicate that adolescents with PCOS are at increased risk for IGT and DM and that the 2-h plasma glucose level after an oral glucose challenge appears to be the most reliable screening test for these abnormalities. Our results need to be corroborated by future studies that determine the prevalence of abnormalities in glucose tolerance among large populations of adolescents, both with and without PCOS. However, as DM may be preventable by lifestyle modifications, we would recommend that adolescents with PCOS undergo periodic screening for abnormal glucose tolerance using 2-h postchallenge plasma glucose levels.

Sex assignment for newborns with ambiguous genitalia and exposure to fetal testosterone: attitudes and practices of pediatric urologists.

OBJECTIVE: Sex assignment to newborns with ambiguous genitalia is controversial. Our objective was to determine the attitudes and practices of pediatric urologists on this subject. STUDY DESIGN: A survey of fellows in the Urology Section of the American Academy of Pediatrics was completed by 185/228 (81%). The survey referred to two cases, masculinized 46XX congenital adrenal hyperplasia (CAH) and 46XY cloacal exstrophy. Questions referred to sex assignment, timing of surgery, decision making process, and respondent demographics. RESULTS: For masculinized 46XX CAH, virtually all respondents favored female sex assignment. The most important factor was potential fertility. For 46XY cloacal exstrophy, two thirds favored the male sex. The most important factor was potential androgen brain imprinting, whereas in selecting female assignment, it was difficulty creating a functional phallus. Respondent characteristics associated with assigning female sex were longer duration in practice (>15 years) and affiliation with training programs. Most respondents advocated a team approach to decision making with parental involvement and early surgery (<18 months). CONCLUSION: Pediatric urologists are in strong consensus about sex assignment for newborns with ambiguous genitalia from CAH, a team approach with parental involvement, and early reconstruction. Yet, there is striking variability in attitudes toward sex assignment for newborns with 46XY cloacal exstrophy, which should be incorporated into the decision-making process with parents.

Variability of markers of inflammation and infection in induced sputum in children with cystic fibrosis.

To determine reproducibility of inflammatory marker concentrations in induced sputum from subjects with cystic fibrosis (CF), 15 nonexpectorating children, 6 to 13 years of age with mild CF lung disease, underwent 3 weekly sputum inductions with 3% saline. Neutrophil elastase concentration and bacterial cultures were reproducible. This study provides useful information for investigators designing trials of anti-inflammatory therapies in CF involving sputum induction.

Dairy consumption, obesity, and the insulin resistance syndrome in young adults: the CARDIA Study.

CONTEXT: Components of the insulin resistance syndrome (IRS), including obesity, glucose intolerance, hypertension, and dyslipidemia, are major risk factors for type 2 diabetes and heart disease. Although diet has been postulated to influence IRS, the independent effects of dairy consumption on development of this syndrome have not been investigated. OBJECTIVE: To examine associations between dairy intake and incidence of IRS, adjusting for confounding lifestyle and dietary factors. DESIGN: The Coronary Artery Risk Development in Young Adults (CARDIA) study, a population-based prospective study. SETTING AND PARTICIPANTS: General community sample from 4 US metropolitan areas of 3157 black and white adults aged 18 to 30 years who were followed up from 1985-1986 to 1995-1996. MAIN OUTCOME MEASURE: Ten-year cumulative incidence of IRS and its association with dairy consumption, measured by diet history interview. RESULTS: Dairy consumption was inversely associated with the incidence of all IRS components among individuals who were overweight (body mass index > or =25 kg/m(2)) at baseline but not among leaner individuals (body mass index < 25 kg/m(2)). The adjusted odds of developing IRS (2 or more components) were 72% lower (odds ratio, 0.28; 95% confidence interval, 0.14-0.58) among overweight individuals in the highest (> or =35 times per week, 24/102 individuals) compared with the lowest (<10 times per week, 85/190 individuals) category of dairy consumption. Each daily occasion of dairy consumption was associated with a 21% lower odds of IRS (odds ratio, 0.79; 95% confidence interval, 0.70-0.88). These associations were similar for blacks and whites and for men and women. Other dietary factors, including macronutrients and micronutrients, did not explain the association between dairy intake and IRS. CONCLUSIONS: Dietary patterns characterized by increased dairy consumption have a strong inverse association with IRS among overweight adults and may reduce risk of type 2 diabetes and cardiovascular disease.