Body mass index trajectories from 2 to 18 years - exploring differences between European cohorts.

BACKGROUND: In recent decades, there has been an increase in the prevalence of childhood overweight in most high-income countries. Within northern Europe, prevalence tends to be higher in the UK compared with the Scandinavian countries. We aimed to study differences in body mass index (BMI) trajectories between large cohorts of children from UK and Scandinavian populations. METHODS: We compared BMI trajectories in participants from the English Avon Longitudinal Study of Parents and Children born in 1991-1993 (ALSPAC) (N = 6517), the Northern Finland Birth Cohorts born in 1966 (NFBC1966) (N = 3321) and 1986 (NFBC1986) (N = 4764), and the Danish Aarhus Birth Cohort born in 1990-1992 (ABC) (N = 1920). We used multilevel models to estimate BMI trajectories from 2 to 18 years. We explored whether cohort differences were explained by maternal BMI, height, education or smoking during pregnancy and whether differences were attributable to changes in the degree of skew in the BMI distribution. RESULTS: Differences in mean BMI between the cohorts were small but emerged early and persisted in most cases across childhood. Girls in ALSPAC had a higher BMI than all other cohorts throughout childhood, e.g. compared with the NFBC1986 BMI was 2.2-3.5% higher. For boys, the difference emerging over time (comparing the two NFBC's) exceeded the differences across populations (comparing NFBC1986, ABC and ALSPAC). BMI distribution demonstrated increasing right skew with age. CONCLUSION: Population-level differences between cohorts were small, tended to emerge very early, persisted across childhood, and demonstrated an increase in the right-hand tail of the BMI distribution.

[Changes of knowledge of HIV-positivity before development of AIDS among Danish patients with AIDS 1988-1997]. / Udvikling i kendskab til hiv-positivitet før aids blandt danske aids-patienter 1988-1997.

We describe the changes in the period of knowledge of HIV positivity before AIDS in the light of the new anti-retroviral treatment regime among all notified Danish AIDS patients 1988-1997. Overall, 29% of the patients were diagnosed with AIDS less than four months after the first positive HIV test, a proportion that decreased through 1988-1995, but then increased. However, the proportion with over five years between positive HIV test and AIDS diagnosis increased from 9% in 1988-1990 to 48% in 1994-1995. A similar trend was seen among men, who have sex with men (MSM). Relatively more heterosexually infected than MSM had less than four months between first positive HIV test and AIDS (44% vs. 25%, p < 0.00001). Among persons known as HIV infected less than four months before AIDS, 51% were notified with Pneumocystis carinii pneumonia, a proportion that was 25% (p < 0.00001) among those known over five years before AIDS. We conclude, that the proportion of Danish AIDS patients known as HIV-infected for less than four months before AIDS recently has increased after several years of decrease, probably due to anti-retroviral treatment.