Gender difference in interactions between MAOA promoter uVNTR polymorphism and negative familial stressors on body mass index among Chinese adolescents.

OBJECTIVES: Monoamine oxidase A (MAOA) modulates metabolism of serotonin and dopamine metabolism, neurotransmitters involved in regulation of appetite and food intake. The gene coding for MAOA contains a 30-bp tandem repeat (uVNTR) polymorphism in its promoter region that has been previously identified to be associated with obesity with mixed findings in the literature. Our goals were to replicate the population effects of this functional polymorphism on obesity risk, and to further explore gender differences and interaction effects with negative stressors. METHODS: Analyses were conducted with data on genotypes, measured weight and height, and self-reported behavioural characteristics among 1101 Chinese adolescents 11-15 years old living in Wuhan, China. RESULTS: Girls with the high-activity allele had significantly lower body mass index (BMI; ß = -0.25 ± 0.98, P = 0.011) compared to those with the low activity allele. Experience of negative familial stressors (e.g., death or illness of family members, hit or scolded by parents and increased quarrelling with parents, parents argued frequently) significantly weakened this protective genetic effect on BMI (P for interaction = 0.043). Stratified analyses showed a significant protective genetic effect on BMI only within the stratum of low stress level (ß = -0.44 ± 0.14, P = 0.002). No similar effect was observed among boys. CONCLUSIONS: Our findings confirm the genetic effects of MAOA uVNTR polymorphism on BMI in a Chinese adolescent population and suggest potential genetic interactions with negative familial stressors.

Are private school students more likely to smoke than public school students in China?

BACKGROUND: Tobacco use is prevalent among adolescents in China in general, however, little is known about tobacco use among students in private schools with an enrollment of 1.5 million. METHOD: In 2001, cross-sectional survey data from 2725 students in grades seven and eight (1307 sampled from private schools and 1418 sampled from public schools) were included. Smoking measures (risk of susceptibility to smoking, smoking onset, ever smoking, smoking in the past 7 days and past 30 days, established smoking) were compared between private and public school students using chi-square test, logistic regression, and survival analysis. RESULTS: Cigarette smoking was more prevalent among private school students than among public school students (private vs. public: 21.9% vs. 12.3% for susceptibility to smoking, 53.9% vs. 38.2% for ever smoking, 22% vs. 12.0% for 30-day smoking, 15.9% vs. 4.0% for 7-day smoking, 4.5% vs. 1.2% for established smoking). Students in private schools are 3.4 to 3.8 times more likely to smoke than students in public schools after the adjustment of important covariates (gender, grade, peer smoking, parental smoking, and parents' occupation). Risk of smoking onset by age was also greater for private school students than for public school students. CONCLUSIONS: Being in private schools was associated with three to four times increases in the likelihood of current cigarette smoking and heightened risk of smoking onset by age. Findings from this study suggest the urgent need to collect additional data on risk and protective factors as well as the willingness to participate in effective tobacco use intervention prevention among private school students.

Ethnic variation in peer influences on adolescent smoking.

Previous research has indicated that the influence of peers on adolescent smoking may differ across ethnic groups. Although many studies have focused on African Americans, Hispanics, and Whites, few studies have included Asian Americans, Pacific Islanders, and multi-ethnic adolescents as distinct groups. Using data from a statewide sample of 5870 eighth-grade adolescents in California, this study examined ethnic differences in the association between peer influence variables and smoking behavior and susceptibility. Informational peer influence (best friends' smoking behavior) and normative peer influence (prevalence estimates of peer smoking) were investigated. We hypothesized that informational peer influences would be stronger among Whites (whose families originate primarily from the individualistic cultures of the USA and Western Europe) than among Asian Americans, Pacific Islanders, Hispanics, and African Americans (whose families originate primarily from collectivist cultures). Conversely, we hypothesized that normative peer influences would be stronger among ethnic minority adolescents from collectivist cultural backgrounds than among Whites. Consistent with previous studies, friends' smoking and prevalence estimates of peer smoking were risk factors for past 30-day smoking and susceptibility to smoking across ethnic groups. The influence of friends' smoking behavior was stronger among Whites than among several other groups: Pacific Islanders, African Americans, and Hispanic/Latinos. The influence of prevalence estimates of peer smoking was stronger among Whites than among multiethnic adolescents. Results indicate that cultural factors may play a role in peer influences on smoking initiation. Smoking prevention interventions for adolescents should address the differences in peer influences across ethnic groups.

Ethnic differences in adolescent smoking prevalence in California: are multi-ethnic youth at higher risk?

OBJECTIVE: Although ethnic differences in adolescent smoking have been well documented, smoking among multi-ethnic adolescents has received little research attention. This study examined smoking prevalence and tobacco related psychosocial risk factors among multi-ethnic adolescents in California, as compared with white, African American, Asian American, and Hispanic adolescents. DESIGN: This study used a cross sectional design. Data were obtained from the independent evaluation of the California Tobacco Control, Prevention, and Education Program. SETTING: Students completed a paper-and-pencil survey in their classrooms. SUBJECTS: Data were collected from a stratified random sample of 5072 eighth grade students (age 13-14 years) in California during the 1996-97 school year. The data were weighted by school enrollment in analyses to make the estimates representative of the population of California students attending public schools. MAIN OUTCOME MEASURES: Outcome variables included self reported smoking prevalence, susceptibility to smoking, access to tobacco, and related attitudes, beliefs, and behaviours. Ethnicity was assessed with a self reported, "check all that apply" question. RESULTS: Results indicated that multi-ethnic adolescents were at higher risk than single-ethnic adolescents on several variables, including 30 day cigarette smoking prevalence, lifetime smokeless tobacco use, buying cigarettes, receiving cigarette offers, and expected friends' reaction if the respondent smoked. For several other variables (lifetime cigarette smoking prevalence, susceptibility to smoking, and number of friends who smoked), Hispanic adolescents were at higher risk than all other ethnic groups including multi-ethnic adolescents. Although susceptibility to smoking was highest among Hispanics, multi-ethnic adolescents scored significantly higher on susceptibility than the three other single-ethnic groups. CONCLUSIONS: Multi-ethnic adolescents may be at increased risk for smoking and may have easier access to cigarettes. Culturally targeted smoking prevention interventions for adolescents should address the unique social challenges faced by multi-ethnic adolescents that may increase their risk for smoking.

Melanoma incidence in Tauranga 1980-9.

This study was a retrospective case series of melanoma taken from pathology records. The denominator population was the nonMaori population of the old Tauranga Hospital Board area. The age standardised incidence over the period 1980-9 was 33.0 per 100,000, males 31.4, females 36.8. Age specific rates showed a double peak in middle aged and elderly age groups due to female rates peaking at 40 to 59 and male rates peaking at 65+. Younger people presented with thinner lesions than old people, women had thinner lesions than men and thin lesions became increasingly common during the decade, being approximately 50% of lesions in 1988-9. The incidence increased by 2.25 times in ten years and Tauranga incidence is between that of Queensland and other Australian states.

A ten year survey of superficial mycoses in the Tauranga district, Bay of Plenty.

Between 1 January 1976 and 31 December 1985, 4086 patients living in Tauranga and its environs were examined mycologically. All were suspected of superficial cutaneous mycoses and the majority were referred by general practitioners. A total of 1085 pathogenic fungi were identified, an isolation rate of 27%. The main pathogens identified in order of frequency were--Candida species; Microsporum canis; Trichophyton rubrum; Malassezia furfur; Epidermophyton floccosum; T mentagrophytes var interdigitale. The positivity rate was slightly higher for patients attending the laboratory compared with specimens collected at the surgeries of medical practitioners. Some seasonal variation was noted.