Pilot study to enhance start-up of a multicenter nutrition intervention trial

A review of methods to measure dietary sodium intake

With the rising prevalence of heart failure, it is imperative to investigate reasons for dietary sodium nonadherence and to develop evidence-based interventions to promote adherence. However, one of the biggest obstacles in studying adherence to a low sodium diet is the imprecision in measurement of dietary sodium intake. The purpose of this article is to critically review current methods used to measure dietary sodium intake. Specifically, 24-hour urine, single- and multiple-day food records, and 24-hour dietary recalls are compared and contrasted. The reliability and validity of these methods are discussed. When choosing a method to measure dietary sodium, it is important also to consider other strengths and weaknesses of each method. The "best" method to be used in research may depend not only on the above information, but also on the research question as well as characteristics of the population under study.

Ethnic comparison of weight loss in the Trial of Nonpharmacologic Interventions in the Elderly

OBJECTIVE

To compare weight loss in blacks and whites in the Trial of Nonpharmacologic Interventions in the Elderly (TONE).

RESEARCH METHODS AND PROCEDURES

TONE enrolled 421 overweight white and 164 overweight black adults, 60 to 79 years old, with blood pressure well-controlled on a single, antihypertensive drug. Drug therapy withdrawal was attempted 3 months after randomization to counseling for weight loss, sodium reduction, both weight loss and sodium reduction, or to usual care, with follow-up for 15 to 36 months after enrollment. Statistical procedures included repeated measures analysis of covariance and logistic and proportional hazards regression.

RESULTS

In the weight-loss condition, net weight change (in kilograms) was -2.7 in blacks and -5.9 in whites (p < 0.001; ethnic difference, p = 0.0002) at 6 months and -2.0 (p < 0.05) in blacks and -4.9 (p < 0.001) in whites at the end of follow-up (ethnic difference, p = 0.007). In weight/sodium, net weight change was -2.1 (p < 0.01) in blacks and -2.8 (p < 0.001) in whites at 6 months, and -1.9 in blacks and -1.7 in whites at the end of follow-up (p < 0.05; ethnic difference, p > 0.5). Exploratory analyses suggested a more favorable pattern of weight change in blacks than in whites from 6 months onward. There was no ethnic difference in blood pressure outcomes.

DISCUSSION

Whites lost more weight than blacks without, but not with, a concurrent focus on sodium reduction.