Abstract Aims Obesity, particularly visceral adiposity, is a key driver of cardiovascular mortality (CVM), yet conventional measures such as body mass index (BMI) inadequately capture fat distribution. The Body Roundness Index (BRI) is a novel anthropometric measure integrating waist circumference and height to better reflect body shape and visceral fat. This study examined the association between BRI and CVM in U.S. adults and across sociodemographic subgroups. Methods and results We analysed data from 31 351 adults (median age 43 yrs, 50% females) aged ≥20 years in NHANES 1999–2018, excluding those with prior cardiovascular disease or cancer. BRI was computed using a validated equation and categorized into quintiles (Q3 as reference). The primary outcome was CVM; secondary outcomes included all-cause, heart disease, and cerebrovascular mortality. Weighted Cox proportional hazards and restricted cubic spline (RCS) models evaluated associations after adjustment for demographic, behavioural, and clinical factors. Subgroup and sensitivity analyses tested consistency and effect modification. During a median follow-up of 10.1 years (IQR: 5.3–14.9 years), 883 cardiovascular deaths occurred. In fully adjusted models, participants in the highest BRI quintile had a 54% higher risk of CVM (HR, 1.54; 95% CI, 1.13–2.08; P = 0.006) vs. Q3. This risk remained high even among those with normal BMI. RCS analysis indicated a modest U-shaped association. Stronger effects were observed among middle-aged adults (45–64 years) and those with higher educational attainment. Conclusion Higher BRI is independently associated with increased cardiovascular mortality, particularly among middle aged adults and those with normal BMI, underscoring its potential as a practical, noninvasive tool for cardiovascular risk stratification. Incorporating BRI into clinical and public health assessment may improve identification of individuals at elevated risk.
Z-coded social determinants of health and cardiovascular risk among patients receiving dialysis
Journal of Nephrology | January 6, 2026 | Volume: 39 | Issue: 3 | Pages: 528-535
Abstract Introduction Cardiovascular disease (CVD) is the leading cause of death among patients with kidney failure on dialysis. Social determinants of health may worsen this risk but are seldom incorporated into prognostic models. ICD-10 Z-codes provide standardized documentation of social determinants of health, yet their prognostic value in dialysis populations remains uncertain. This study examined whether Z-coded social determinants of health are associated with adverse cardiovascular outcomes and mortality among patients receiving dialysis for kidney failure. Methods A retrospective cohort study was conducted using the TriNetX Research Network (2010–2024), encompassing de-identified data from 103 institutions. Adults with kidney failure on chronic dialysis were stratified by the presence of ICD-10 Z-codes (Z55–Z65). Propensity score matching (1:1) balanced demographics, comorbidities, medications, and laboratory values. Primary outcomes were all-cause mortality and hospitalization; secondary outcomes included acute heart failure, myocardial infarction, stroke, cardiac arrest, bradyarrhythmias, and ventricular tachycardia. Results After matching, mean age was 62 years, and 42.4% were female in the Z-code cohort versus 41.2% in controls. Over one year, mortality occurred in 12.5% versus 10.9% (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.15–1.29) and all-cause hospitalizations in 57.3% versus 53.1% (HR, 1.22; 95% CI, 1.19–1.26). Cardiovascular complications were consistently higher in Z-coded patients, including heart failure (24.3% vs 20.5%; HR, 1.29), myocardial infarction (8.0% vs 7.1%; HR, 1.19), stroke (6.6% vs 6.2%; HR, 1.13), cardiac arrest (3.8% vs 3.1%; HR, 1.29), and bradyarrhythmias (6.9% vs 5.5%; HR, 1.33). Discussion Among patients with kidney failure, documented Z-coded social risk factors were associated with greater mortality and cardiovascular morbidity. Incorporating social determinants of health documentation into nephrology care may improve risk stratification and inform targeted interventions.