Predicting body composition from anthropometry and bioimpedance in marginally undernourished adolescents and young adults.

Body-composition prediction equations were developed using data from a sample of 201 female and male Guatemalan ladinos (ie, people of Amerindian-European descent) aged 11-25 y. Fat-free mass (FFM) values were estimated from body density by using the two-component model and age- and sex-specific values for the density of FFM. The root-mean-square error (RMSE) of the best model predicting FFM from a set of simple anthropometric variables was 1.59 kg for females and 1.90 kg for males. The addition of more extensive anthropometry to the set of candidate predictors reduced the RMSE to 1.42 kg for females and 1.88 kg for males. The subsequent addition of a bioelectrical impedance measure (Ht2/R) further reduced the RMSE to 1.32 kg for females and 1.82 kg for males. These results suggest that for a marginally undernourished population with relatively little body fat, simple anthropometrics are as useful as more sophisticated measures for the prediction of body composition.

Prostate cancer: demographic and behavioral correlates of stage at diagnosis among blacks and whites in North Carolina.

OBJECTIVES: Although stage at diagnosis is one of the most important predictors of survival from prostate cancer, demographic factors, screening practices, and knowledge and beliefs associated with stage at diagnosis have not been well documented, particularly by race. METHODS: We conducted telephone interviews with 117 black and 114 white men diagnosed with prostate cancer to identify the demographic factors, healthcare-seeking behaviors, and prostate cancer-related knowledge, attitudes, and practices associated with stage. The sample was stratified by stage at diagnosis and was composed of men 50 to 74 years old who resided in a contiguous 63-county region in North Carolina and who were diagnosed at 1 of 16 participating hospitals. RESULTS: Among blacks, stage was inversely correlated with income (P = 0.04) and health insurance status (P < or = 0.001); among whites, stage was not associated with income or health insurance status, but approached significance with marital status (P = 0.06). Awareness of prostate cancer before diagnosis tended to decline with advancing stage among black men (P = 0.07), but was high for all stages (greater than 93%) among whites. Report of a prostate-specific antigen screen was inversely correlated with stage among black men (P = 0.01); a trend was observed among whites but was not significant (P = 0.20). Knowledge of prostate cancer risk factors was not significantly associated with stage for blacks or whites. Less than one third of men in each race and stage group knew that black men are at increased risk of prostate cancer. CONCLUSIONS: Demographic and other factors vary with stage and should be considered when designing and targeting interventions to reduce late diagnosis of prostate cancer.