Effect of salt substitution on community-wide blood pressure and hypertension incidence.

Replacement of regular salt with potassium-enriched substitutes reduces blood pressure in controlled situations, mainly among people with hypertension. We report on a population-wide implementation of this strategy in a stepped-wedge cluster randomized trial (NCT01960972). The regular salt in enrolled households was retrieved and replaced, free of charge, with a combination of 75% NaCl and 25% KCl. A total of 2,376 participants were enrolled in 6 villages in Tumbes, Peru. The fully adjusted intention-to-treat analysis showed an average reduction of 1.29 mm Hg (95% confidence interval (95% CI) (-2.17, -0.41)) in systolic and 0.76 mm Hg (95% CI (-1.39, -0.13)) in diastolic blood pressure. Among participants without hypertension at baseline, in the time- and cluster-adjusted model, the use of the salt substitute was associated with a 51% (95% CI (29%, 66%)) reduced risk of developing hypertension compared with the control group. In 24-h urine samples, there was no evidence of differences in sodium levels (mean difference 0.01; 95% CI (0.25, -0.23)), but potassium levels were higher at the end of the study than at baseline (mean difference 0.63; 95% CI (0.78, 0.47)). Our results support a case for implementing a pragmatic, population-wide, salt-substitution strategy for reducing blood pressure and hypertension incidence.

Parental body mass index and blood pressure are associated with higher body mass index and blood pressure in their adult offspring: a cross-sectional study in a resource-limited setting in northern Peru.

OBJECTIVES: High body mass index (BMI) and blood pressure (BP) are major contributors to the high burden of non-communicable diseases in adulthood. Individual high-risk and population approaches for prevention require newer strategies to target these risk factors and focusing on the family to introduce prevention initiatives appears as a promising scenario. Characterisation of the relationship between BMI and BP among the adult members of a given family merits evaluation. We conducted a secondary analysis of an implementation study in Tumbes, Peru, benefiting from data derived from families with at least one adult offspring. METHODS: The exposures of interest were the BMI, systolic BP (SBP) and diastolic BP (DBP) of the mother and father. The outcomes were the BMI, SBP and DBP of the offspring. Mixed-effects linear regression models were conducted. RESULTS: The mean age of the offspring, mothers and fathers was 29 (SD: 9.5), 54 (SD: 11.8) and 59 (SD: 11.6) years, respectively. Father's BMI was associated with a quarter-point increase in offspring BMI, regardless of the sex of the offspring. Mother's BMI had a similar effect on the BMI of her sons, but had no significant effect on her daughters'. Mother's SBP was associated with almost one-tenth of mmHg increase in the SBP of the adult offspring. There was no evidence of an association for DBP. CONCLUSIONS: In families with adult members, the higher the parents' BMI and SBP, the higher their adult offspring's levels will be.

Assessing delay and lag in sagittal trunk control using a tracking task.

Slower trunk muscle responses are linked to back pain and injury. Unfortunately, clinical assessments of spine function do not objectively evaluate this important attribute, which reflects speed of trunk control. Speed of trunk control can be parsed into two components: (1) delay, the time it takes to initiate a movement, and (2) lag, the time it takes to execute a movement once initiated. The goal of this study is to demonstrate a new approach to assess delay and lag in trunk control using a simple tracking task. Ten healthy subjects performed four blocks of six trials of trunk tracking in the sagittal plane. Delay and lag were estimated by modeling trunk control for predictable and unpredictable (control mode) trunk movements in flexion and extension (control direction) at movement amplitudes of 2°, 4°, and 6° (control amplitude). The main effect of control mode, direction, and amplitude of movement were compared between trial blocks to assess secondary influencers (e.g., fatigue). Only control mode was consistent across trial blocks with predictable movements being faster than unpredictable for both delay and lag. Control direction and amplitude effects on delay and lag were consistent across the first two trial blocks and less consistent in later blocks. Given the heterogeneity in the presentation of back pain, clinical assessment of trunk control should include different control modes, directions, and amplitudes. To reduce testing time and the influence of fatigue, we recommend six trials to assess trunk control.

Male circumcision and risk of HIV acquisition among MSM.

OBJECTIVES: To assess the association between male circumcision, insertive anal sex practices, and HIV acquisition in a cohort of MSM. METHODS: Data were from 1824 HSV-2-seropositive, HIV-seronegative MSM, 1362 (75%) from Peru and 462 (25%) from the US, who participated in a randomized placebo-controlled trial of HSV-2 suppression for HIV prevention (HPTN 039). Circumcision status was determined by examination at enrollment. HIV testing was done every 3 months for up to 18 months. Partner-specific sexual behavior for up to the last three partners during the previous 3 months was analyzed. RESULTS: There was no significant association between male circumcision and HIV acquisition in univariate analysis [relative risk (RR) = 0.84, 95% confidence interval (CI) 0.50-1.42]. In a prespecified multivariate analysis that assumed a linear relationship between the proportion of insertive acts and effect of circumcision on HIV acquisition, the interaction between circumcision and proportion of insertive acts was not significant (P = 0.11). In an exploratory analysis that categorized behavior with recent partners by proportion of insertive acts (<60 or ≥60% insertive acts), circumcision was associated with a nonstatistically significant 69% reduction in the risk of HIV acquisition (RR = 0.31, 95% CI 0.06-1.51) among men who reported at least 60% of insertive acts with recent male partners. CONCLUSION: Circumcision does not have a significant protective effect against HIV acquisition among MSM from Peru and US, although there may be reduced risk for men who are primarily insertive with their male partners. This association needs to be investigated across diverse cohorts of MSM.

The abandoned radical hysterectomy for cervical cancer: clinical predictors and outcomes.

Objective. Cervical cancer patients who had an abandoned radical hysterectomy were evaluated for preoperative clinical predictors, complication rates, and outcomes. Study Design. IRB approval was obtained for this retrospective analysis and chart review was performed. Results. From 268 women with early-stage (IA2 to IIA) cervical cancer, 19 (7%) had an abandoned hysterectomy for finding grossly positive lymph nodes (84%) or pelvic spread of tumor (16%). No clinical characteristics clearly identified women preoperatively at risk of having an abandoned hysterectomy. In the abandoned group, 26% suffered major morbidities, compared to 34% in the completed group (OR 0.69, [CI 0.16-2.57], P = .789). Thirty-seven percent recurred in the abandoned group, compared to 18% in the completed group (P = .168). Overall survival in the abandoned group was 73% versus 80% in the completed group (P = .772). Conclusion. The practice of abandoning a planned radical hysterectomy for unexpected metastatic disease may not worsen the outcome.

Nonparametric and Semiparametric Analysis of Current Status Data Subject to Outcome Misclassification.

In this article, we present nonparametric and semiparametric methods to analyze current status data subject to outcome misclassification. Our methods use nonparametric maximum likelihood estimation (NPMLE) to estimate the distribution function of the failure time when sensitivity and specificity are known and may vary among subgroups. A nonparametric test is proposed for the two sample hypothesis testing. In regression analysis, we apply the Cox proportional hazard model and likelihood ratio based confidence intervals for the regression coefficients are proposed. Our methods are motivated and demonstrated by data collected from an infectious disease study in Seattle, WA.