Applied nutritional investigationsDoes dietary recall adequately assess sodium, potassium, and calcium intake in hypertensive patients?
Introduction
Nutritional sodium, potassium, and calcium are considered regulators of blood pressure (BP) [1]. There is considerable evidence relating sodium intake to BP. Analysis of the International Cooperative Study on the relation of Sodium and Potassium to Blood Pressure (INTERSALT), which included more than 10 000 subjects, showed a highly significant relation between salt intake and BP [2]. Controlled clinical trials such as the Trial of Nonpharmacologic Intervention in the Elderly (TONE) and the Dietary Approaches to Stop Hypertension-Sodium trials have repeatedly demonstrated that low-sodium intake significantly decreases BP [3], [4]. Salt restriction is therefore a primary goal in all patients with hypertension and especially in those who are sensitive to salt.
Increased sodium intake is associated with increased BP, whereas increased potassium and calcium intake may slightly decrease BP [5]. Therefore, the assessment of the exact intake of these electrolytes in patients with hypertension is of major clinical importance.
The exact intake cannot be measured precisely but can be extrapolated from dietary recall questionnaires or 24-h urine collection under stable conditions [6]. Previous studies have reported a strong positive association between dietary intake as assessed from patients’ food recall and urinary excretion of sodium, potassium, and calcium [6], [7], [8], [9], [10], [11]. However, recent studies have shown that dietary recall underestimates sodium and potassium intakes [12], [13]. We evaluated these two methods of electrolyte intake assessment in a group of patients who had hypertension and were enrolled to maintain a diet low in sodium and high in potassium and calcium.
The aim of the present study was to correlate these two modes of measurement to provide a better estimation of how much dietary recall reflects real electrolyte intake.
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Patients
Thirty-six patients (26 men and 10 women, 24 to 67 y of age, mean age 46 ± 8 y) from our outpatient clinic participated in the study. All participants had essential hypertension and were on no drug therapy (n = 20) or monotherapy (n = 16). Patients treated with diuretics were excluded from the study as were all patients with secondary hypertension, ischemic heart disease, congestive heart failure, renal failure (creatinine > 1.5 mg/dL), and controlled diabetes mellitus. Patients were included
Patients’ characteristics
Thirty-six patients participated in the study. Most patients were overweight with an increased waist-to-hip ratio. Patient characteristics and baseline parameters are presented in Table 1.
Effect of dietary intervention on BP and heart rate
After 3 mo of dieting, systolic BP decreased only slightly by 2.5 mmHg (95% confidence interval = -6.5 to 1.5) and diastolic BP decreased by 0.9 mmHg (95% confidence interval = -4 to 2.2, P non-significant for both). Heart rate remained unchanged.
Effect of diet on estimated sodium intake and urinary sodium excretion
Estimated sodium intake decreased from 122 ± 12 mmol/d at
Discussion
Assessment of sodium, potassium, and calcium intakes is very important in the management of hypertension. The exact intake of these electrolytes over time generally cannot be measured precisely. It is well established that, under stable conditions, daily sodium intake almost equals daily urinary sodium excretion [15], [16]. However, collection of urine for 24 h is inconvenient and may be incomplete. Therefore, dietary recall may be an alternative to estimate sodium dietary intake [17], [18].
The
References (20)
- et al.
The measurement of sodium and potassium intake
Am J Clin Nutr
(1985) - et al.
Sodium and potassium intakes and excretions of normal men consuming sodium chloride or a 1:1 mixture of sodium and potassium chlorides
Am J Clin Nutr
(1977) - et al.
Computerized collection and analysis of dietary intake information
Comput Methods Programs Biomed
(1989) - et al.
Body fluid homeostasis in man. A contemporary overview
Am J Med
(1981) Nutritional factors in blood pressure
J Hum Hypertens
(1994)The INTERSALT studyan addition to the evidence on salt and blood pressure, and some implications
J Hum Hypertens
(1989)- et al.
Sodium reduction and weight loss in the treatment of hypertension in older personsa randomized controlled trial of nonpharmacologic interventions in the elderly (TONE)
JAMA
(1998) - et al.
Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet
N Engl J Med
(2001) - et al.
Reduction in blood pressure with a low sodium, high potassium, high magnesium salt in older subjects with mild to moderate hypertension
BMJ
(1994) - et al.
The relationship between dietary intake and urinary excretion of sodium, potassium, calcium and magnesiumBelgian Interuniversity Research on Nutrition and Health
J Hum Hypertens
(1990)
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