Study of the Effects of DASH Style Diet and Oxalate Restricted Diet on Urinary Supersaturation Which is a Major Predisposing Factor for Nephrolithiasis
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 48
- 试验地点
- 2
- 主要终点
- urinary oxalate
研究概览
简要总结
Oxalate restricted diet is routinely prescribed in clinical practice of nephrolithiasis patients with hyperoxaluria. The effect of dietary oxalate on urinary oxalate is however controversial. Some studies do not implicate dietary oxalate as a major risk factor for nephrolithiasis. The Dietary Approaches to Stop Hypertension (DASH) diet, which is high in fruits and vegetables, moderate in low-fat dairy products, and low in animal protein represents a novel potential means of kidney stone prevention. The effect of a DASH-style diet on relative urinary supersaturations is however uncertain. Higher consumption of fruits and vegetables may increase urinary oxalate but also increases urinary citrate, an important inhibitor of calcium saturation.All the above data lead us to hypothesize that a DASH diet other than an oxalate restricted diet, which is routinely administered in clinical practice, might be beneficial in lowering urinary relative supersaturations of calcium oxalate in recurrent stone formers with hyperoxaluria.
Recurrent stone formers with hyperoxaluria (urine oxalate>32.8) are allocated into 2 groups. The first group is prescribed an oxalate restricted diet. The second group are asked to follow a calorie-controlled DASH diet plan while drink water in the same amounts. 24-h urine is collected 2 times before study visits at baseline, 1 time on week 6 and 2 times at the end of the study.
详细描述
After a run-in period of 3 weeks patients are allocated into 2 groups. The first group is prescribed an oxalate restricted diet. They are instructed to avoid oxalate-rich foods such as spinach, rhubarb, beets, chocolate, cereals, nuts, tea, wheat bran, and strawberries and to drink water in amounts of roughly 2 L during cold weather and 3 L during warm/hot weather. The second group is asked to follow a calorie-controlled DASH diet plan. DASH is an eating pattern recommended by the 2005 Department of Health and Human Services Dietary Guidelines for Americans as a model of healthy eating for the majority of individuals in the population . This group eats a diet which includes higher fruit, vegetables, and low-fat dairy products and lower in saturated fat, total fat, and cholesterol, containing more whole grains and fewer refined grains, sweets, and red meat. The calcium, potassium, and magnesium of the DASH diet is higher. The DASH diet contains 2,400 mg Na per day . The servings, mentioned in the publication of the National Institutes of Health regarding the DASH eating plan, are used as a practical guideline. Lower consumption of meat and higher consumption of low-fat dairies, vegetable, fruit, whole-grain cereals, and legumes distinguish between the DASH trial and the weight-reduction diet.
We determine the caloric needs for each person in both groups individually according to the Harris Benedict Formula:
Metric BMR Formula Women: BMR= 655 + ( 9.6 × weight in kilos ) + ( 1.8 × height in cm ) - ( 4.7 × age in years ) Men: BMR= 66 + ( 13.7 × weight in kilos ) + ( 5 × height in cm ) - ( 6.8 × age in years )
To determine their total daily calorie needs, multiply their BMR by the appropriate activity factor, as follows:
If they are sedentary (little or no exercise) : Calorie-Calculation = BMR × 1.2 If they are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR × 1.375 If they are moderately active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR × 1.55 If they are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR × 1.725 If they are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR × 1.9
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •A history of at least one time kidney stone
- •more than 18 years old
- •stones at least 50% calcium oxalate
- •normal renal function, -sterile urine samples, -
- •normal blood pressure
排除标准
- •primary hyperoxaluria (urine oxalate>100 mg/24h)
- •diabetes mellitus
- •hepatic, thyroid, parathyroid, CKD or immunologic disease
研究组 & 干预措施
Oxalate restricted
After a run-in period of 3 weeks patients are allocated into 2 groups. The Oxalate restricted group is prescribed an oxalate restricted diet. They are instructed to avoid oxalate-rich foods such as spinach, rhubarb, beets, chocolate, cereals, nuts, tea, wheat bran, and strawberries and to drink water in amounts of roughly 2 L during cold weather and 3 L during warm/hot weather.
干预措施: diet (Behavioral)
DASH diet
The second group is asked to follow a calorie-controlled DASH diet plan. DASH is an eating pattern recommended by the 2005 Department of Health and Human Services Dietary Guidelines for Americans as a model of healthy eating for the majority of individuals in the population. This group eats a diet which includes higher fruit, vegetables, and low-fat dairy products and lower in saturated fat, total fat, and cholesterol, containing more whole grains and fewer refined grains, sweets, and red meat.
干预措施: diet (Behavioral)
结局指标
主要结局
urinary oxalate
时间窗: 2 months
24-h urine including urine oxalate is collected 2 times before study visits at baseline, and 2 times at the end of the study which is 2 months.
次要结局
- urinary calcium oxalate supersaturation(2 months)
研究者
Nazanin Noori
MD, PhD
Shahid Beheshti University of Medical Sciences