DXA-derived body composition and blood pressure in underweight and overweight adolescent girls in rural and urban South Africa
- 1University of the Witwatersrand Johannesburg
Abstract
BackgroundElevated blood pressure (BP) during adolescence is an early marker of cardiovascular risk, particularly in settings experiencing under and overnutrition. However, the relationship between detailed body composition and BP across nutritional extremes remains poorly understood. We examined associations between dual-energy X-ray absorptiometry (DXA)-derived body composition and BP among underweight and overweight South African adolescent girls to assess multilevel correlates of BP.
MethodsThe Ntshembo trial included 1268 girls 13-19-years from rural Agincourt and urban Soweto. Participants were selected as underweight or overweight. BP was measured in triplicate at a single visit and classified into clinic BP category ranges. DXA provided measures of fat mass (FM), fat-free soft tissue mass (FFSTM), and related indices. Results: Mean SBP and DBP were 110.0{+/-}11.2mmHg and 68.7{+/-}8.2mmHg, respectively; 21.1% of participants had elevated or hypertensive-range BP. Overweight adolescents had higher SBP and BP categories compared with underweight adolescents. DXA-derived adiposity measures were positively associated with SBP and BP category. FFSTM showed strong association with SBP. Higher FM/FFSTM was associated with elevated (RRR=4.25, 95%CI:1.77-10.20) and hypertensive-range BP (RRR=19.04, 95%CI:6.43-56.40). Caregiver hypertensive-range BP was independently associated with adolescent hypertensive-range BP (RRR=1.72-1.82). Sedentary behaviour independently associated with elevated BP, highlighting a modifiable behavioural target alongside intergenerational risk. Associations were more consistent for SBP than DBP.
Conclusionsboth FM and FFSTM positively associated with BP, particularly SBP. Regional percentage analyses were consistent with higher BP when a greater proportion of total fat was distributed centrally rather than peripherally.
Related
- A Randomized Clinical Trial of a Standardized Pumpkin-Seed-Derived Peptide Extract: Body Composition Outcomes and Exploratory Analysis by Baseline Adiposity in Overweight Adults
- Growth trajectories and risk of underweight and overweight in childhood cancer patients and survivors: a longitudinal multicentre cohort study protocol
- Body mass index modifies cardiovascular risk across blood pressure categories, particularly among underweight adults with hypertension: a 6.3 million‑person nationwide Japanese cohort study
- Broader factors associated with current adolescent overweight/obesity status in YRBSS 2023: Survey-aware analysis and calibrated AI-assisted classification
- Family and community pressure, obesity-related behaviours, and psychological wellbeing among female adolescents with overweight or obesity: a qualitative study.
BibTeX
@misc{crouch2026dxaderived,
title = {{DXA-derived body composition and blood pressure in underweight and overweight adolescent girls in rural and urban South Africa}},
author = {S. H. Crouch and A. Craig and D. E. Mathatha and L. K. Micklesfield and R. Retnakaran and N. Christofides and C. Desmond and S. Sharp and K. K. Ong and S. M. Tollman and K. Kahn and S. Norris},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.15.26363182},
url = {https://www.medrxiv.org/content/10.64898/2026.09.15.26363182v1},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - DXA-derived body composition and blood pressure in underweight and overweight adolescent girls in rural and urban South Africa
AU - S. H. Crouch
AU - A. Craig
AU - D. E. Mathatha
AU - L. K. Micklesfield
AU - R. Retnakaran
AU - N. Christofides
AU - C. Desmond
AU - S. Sharp
AU - K. K. Ong
AU - S. M. Tollman
AU - K. Kahn
AU - S. Norris
PY - 2026
DA - 2026/09/15
PB - medRxiv
DO - 10.64898/2026.09.15.26363182
UR - https://www.medrxiv.org/content/10.64898/2026.09.15.26363182v1
AB - BackgroundElevated blood pressure (BP) during adolescence is an early marker of cardiovascular risk, particularly in settings experiencing under and overnutrition. However, the relationship between detailed body composition and BP across nutritional extremes remains poorly understood. We examined associations between dual-energy X-ray absorptiometry (DXA)-derived body composition and BP among underweight and overweight South African adolescent girls to assess multilevel correlates of BP. MethodsThe Ntshembo trial included 1268 girls 13-19-years from rural Agincourt and urban Soweto. Participants were selected as underweight or overweight. BP was measured in triplicate at a single visit and classified into clinic BP category ranges. DXA provided measures of fat mass (FM), fat-free soft tissue mass (FFSTM), and related indices. Results: Mean SBP and DBP were 110.0{+/-}11.2mmHg and 68.7{+/-}8.2mmHg, respectively; 21.1% of participants had elevated or hypertensive-range BP. Overweight adolescents had higher SBP and BP categories compared with underweight adolescents. DXA-derived adiposity measures were positively associated with SBP and BP category. FFSTM showed strong association with SBP. Higher FM/FFSTM was associated with elevated (RRR=4.25, 95%CI:1.77-10.20) and hypertensive-range BP (RRR=19.04, 95%CI:6.43-56.40). Caregiver hypertensive-range BP was independently associated with adolescent hypertensive-range BP (RRR=1.72-1.82). Sedentary behaviour independently associated with elevated BP, highlighting a modifiable behavioural target alongside intergenerational risk. Associations were more consistent for SBP than DBP. Conclusionsboth FM and FFSTM positively associated with BP, particularly SBP. Regional percentage analyses were consistent with higher BP when a greater proportion of total fat was distributed centrally rather than peripherally.
ER -