Cardiometabolic Profile in Young Adults With Diverse Cigarette Smoking Histories: A Longitudinal Study From...

For the first time, the present study investigated smoking trajectory and cardiometabolic profile from adolescence to young adulthood in a middle-income developing country facing a high prevalence of smoking and cardiovascular disease-related outcomes.

Data on 1082 adolescents (12-18 years of age) who participated in the TLGS (Tehran Lipid and Glucose Study) were gathered, and participants were followed for a median of 12.5 years (baseline: 1999-2002, last follow-up: 2014-2017). Participants were categorized as non/rare smokers, experimenters, and escalators using group-based trajectory models. Statistical analysis was used to compare the trajectory groups' cardiometabolic components, clinical characteristics, and cardiometabolic changes due to the individuals' placement in experimenter and escalator groups compared with non/rare smokers. The smoking trajectory groups in young adulthood differ significantly in blood pressure, triglycerides, high-density lipoprotein cholesterol, waist circumference, and body mass index, with the escalator group having the highest risk values for each component. Significant differences were observed in blood pressure (P=0.014), triglycerides (P<0.001), and waist circumference (P<0.001) status after using clinical cut points. The adjusted linear regression revealed that the escalator group had 3.16 mm Hg-lower systolic blood pressure SBP (P=0.016), 2.69 mm Hg-lower diastolic blood pressure (P=0.011), and 4.42 mg/dL-lower high-density lipoprotein cholesterol (P=0.002), compared with the non/rare smoker group.

Despite elevated risks in unadjusted analyses for all cardiometabolic components among smokers, our study identified a modest protective link between early smoking and blood pressure in addition to a remarkable harmful association with high-density lipoprotein cholesterol levels exclusively in the escalator group during the developmental stage to young adulthood, using adjusted analyses.