Growth patterns in early childhood and cardiovascular structure and function at 4 years old: A prospective cohort study.

BACKGROUND AND AIMS: Childhood overweight and obesity are lifetime risk factors for cardiovascular disease but the relationship between dynamic body mass index (BMI) change and cardiovascular structure and function in early childhood remains unclear. METHODS AND RESULTS: This cohort study consisted 525 participants with 6 distinct representative growth patterns to examine the associations between BMI growth patterns and subsequent cardiovascular structure and function at age 4. BMIs were obtained at birth, 2 and 4 years old. Cardiovascular assessments were performed, including blood pressure (BP), cardiac geometric parameters, left ventricular (LV) function, speckle-tracking, integrated backscatter analysis and carotid intima-media thickness. Compared to the stable normal BMI pattern, children with the stable overweight (OW) pattern had significantly greater LV anatomic parameters in fully adjusted models. Children with the catch-up (CU) pattern revealed a uniform trend and had poorer strain. LV diameters and integrated backscatter signals were larger for those with BMI gain and lose pattern. Children with BMI lose pattern showed improved tendency involving LV mass index and BP. Both OW and CU patterns were associated with high systolic BP [odds ratio (95% CI): OW: 3.67 (1.08, 12.47); CU: 4.24 (1.75, 10.28)]. Compared to static BMI measurements at birth, 2 and 4 years old, dynamic BMI growth patterns were more predictive of cardiovascular structure and function at 4. CONCLUSIONS: Children with overweight-related BMI growth patterns in early childhood experienced undesirable cardiovascular functional or structural changes as early as 4 years old, indicating that early intervention is needed and potentially beneficial.

Two-stage identification of SNP effects on dynamic poplar growth.

This project proposes an approach to identify significant single nucleotide polymorphism (SNP) effects, both additive and dominant, on the dynamic growth of poplar in diameter and height. The annual changes in yearly phenotypes based on regular observation periods are considered to represent multiple responses. In total 156,362 candidate SNPs are studied, and the phenotypes of 64 poplar trees are recorded. To address this ultrahigh dimensionality issue, this paper adopts a two-stage approach. First, the conventional genome-wide association studies (GWAS) and the distance correlation sure independence screening (DC-SIS) methods (Li et al., 2012) were combined to reduce the model dimensions at the sample size; second, a grouped penalized regression was applied to further refine the model and choose the final sparse SNPs. The multiple response issue was also carefully addressed. The SNP effects on the dynamic diameter and height growth patterns of poplar were systematically analyzed. In addition, a series of intensive simulation studies was performed to validate the proposed approach.