03/21/2024
By Judith Hull
Candidate: Liam Fouhy
Degree: Sc.D. in Public Health, Epidemiology
Defense Date: Tuesday, April 9, 2024
Time: 10 a.m.
Location: Riverview Suites, Room 154
Dissertation Committee:
Chair: Sabrina Noel, Ph.D., RD
David Cornell, PT, DPT, Ph.D, FACSM
Wenjun Li, Ph.D.
Chao-Qiang Lai, Ph.D.
Katherine Tucker, Ph.D.
Abstract
Background: Puerto Rican adults living on the U.S. mainland have high prevalence of osteoporosis (OP) and psychosocial stress, compared with other racial and ethnic groups in the United States. OP and OP-related fractures can result in significant individual and societal burden, including hospital admissions, skilled nursing facility admissions and, in some cases, death. Nearly 5 million Puerto Ricans live in the U.S. mainland, thus, better understanding the pathology of health issues that affect this underserved population is imperative. Emerging evidence suggests that psychosocial stress may be a risk factor for OP. Further, genetic predisposition to OP and potential interactions with dietary behaviors is another growing area in the bone field. Little is known about genetics and health factors, including stress, associated with OP in Puerto Rican adults living on the US mainland. To our knowledge, there are no studies of the potential interaction between dietary quality and genetic risk factors on OP in this population.
Objective: To determine psychosocial, dietary and genetic risk factors associated with OP in Puerto Rican adults living on the US mainland by: (1) determining the relationship between subjective quantitative stress measures and objective measures of physiological stress, (2) quantifying the relationship between physiological stress biomarkers with OP and investigating if diet moderates this association, and (3) discovering genetic variants associated with OP in Puerto Rican adults and potential interactions between dietary quality and these genetic variants on OP.
Methods: All analyses were conducted using data from the Boston Puerto Rican Health Study (n=1500, aged 45-75 y at baseline) from questionnaire and biological measurements. Multivariable regression methods were used to examine relationships between subjective psychosocial stress questionnaire data and physiological stress biomarkers. Multivariable linear and logistic regression models were employed to assess relationships between bone mineral density (BMD) and odds of OP with physiological measures of stress. Lastly, multivariable linear and logistic regression models were used to determine associations between genetic variants BMD and OP.
Results: Urinary epinephrine (biomarker of stress) was associated with questionnaires related to depression and perceived stress, but other biomarkers of stress (DHEAS, norepinephrine and cortisol) were not. Greater concentration of urinary epinephrine was also associated with lower mean BMD and higher odds of OP in males only. No associations were seen for DHEAS, norepinephrine or cortisol, in males or females. Several genetic loci were related to BMD and OP, and several of these showed interaction with Dietary Approaches to Stop Hypertension (DASH) diet score on odds of OP.
Conclusions: Puerto Rican adults from the Greater Boston area have higher than previously appreciated prevalence of OP. Their unique genetic profiles, coupled with high levels of psychosocial stress and poor diet quality may contribute to OP. Results from this dissertation suggest that management of psychosocial stress, higher dietary quality and consideration of genetic risk may be important for management and treatment of osteoporosis in this population.