Smoking behaviour and biological maturation in males and females: a 20-year longitudinal study. Analysis of data from the Amsterdam Growth and HealthLongitudinal Study

Primary objective: (1) Describe the longitudinal smoking behaviour of boys and girls during adolescence in relation to calendar age. skeletal age, Nea rs front peak height velocity (PHV) and years from menarche (in girls). (2) and (3) Investigate the timing of biological maturation (early or late mat uration) in relation to smoking behaviour in adolescence and in adulthood ( i.e. calendar age 32/33). Hypothesis: We hypothesized skeletal age. years from PHV and Nears from men arche to be better predictors of smoking than calendar age. Research design: This study is part of the Amsterdam Growth and Health Long itudinal Study (AGAHLS) that was started in 1977 with 619 pupils front two secondary schools (mean age 13.0 SD 0.6). Methods and procedures: Smoking behaviour was assessed four times between 1 977 and 1980 and once in 1996/1997. Calendar age and skeletal age were Meas ured annually whereas height and menarche were Measured every 4 months. Mat uration rate (skeletal age Minus calendar age), age it PHV and age at menar che were used to estimate timing of biological maturation. Generalized Esti mating Equation (GEE) analysis was used to study maturation rate in relatio n to smoking during adolescence, whereas logistic regression analyses were used to study mean maturation rate, Nears from PHV and years from menarche in relation to smoking in adulthood. Outcomes and results: Skeletal age, years front PHV and years from menarche are no better predictors or smoking during adolescence than calendar age. The prevalence of smoking rises gradually with the increase in all four est imates of biological Maturation. Timing of biological maturation was positi vely related to smoking but only at calendar age 13 (OR 3.34, CI 1.58, 7.07 ). None of the three measures to estimate timing or biological Maturation w as significantly related to smoking status in adulthood.