Association of urinary pH with body weight in nephrolithiasis

Maalouf, Naim M.; Sakhaee, Khashayar; Parks, Joan H.; Coe, F. L.; Adams‐Huet, Beverley; Pak, Charles Y.C.

doi:10.1111/j.1523-1755.2004.00522.x

Cited by 353 publications

(228 citation statements)

References 25 publications

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“…The inverse relationship reported by Maalouf et al (2004) for body weight and urinary pH remained stable when these authors adjusted 24h-UpH for the body's acid load using urinary sulfate, as a raw estimate of NAE. However, whether an NAE-adjusted 24-h urinary pH does actually correlate with adiposity can only be proved if biochemically analyzed NAE is used instead of excretion parameters as sulfate because a high protein intake and consequently high sulfate excretion does not automatically result in a high NAE (Sebastian et al, 2002;.…”

Section: Introductionmentioning

confidence: 92%

“…It can be quantified in 24-h urines by titration methods (Remer andManz, 1994, 1995a;Sebastian et al, 2002) and can be estimated by the potential renal acid load (PRAL), reflecting the dietary acidity (Remer and Manz, 1995b; and a body surface area (BSA)-dependent organic acid anion component (OA), reflecting primarily endogenous acids (Manz et al, 1984;Berkemeyer and Remer, 2006). Recently, Maalouf et al (2004) reported an inverse relationship between 24-h urinary pH (24h-UpH) and body weight, the latter taken as an indicator of obesity and peripheral insulin resistance, in patients with nephrolithiasis. Consequently, excess adipose tissue could contribute to lower urinary pHs.…”

Section: Introductionmentioning

confidence: 99%

“…The fact that the NAE component OA depends on BSA, also implies potentially higher NAE values with excess adipose tissue. The most frequently used crude indicators of obesity are body mass index (BMI) (Siener et al, 2004;Watts et al, 2006) and body weight (Maalouf et al, 2004;Kuriyama, 2006); however, measurements of percent body fat would be preferable (Watts et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

“…However, whether an NAE-adjusted 24-h urinary pH does actually correlate with adiposity can only be proved if biochemically analyzed NAE is used instead of excretion parameters as sulfate because a high protein intake and consequently high sulfate excretion does not automatically result in a high NAE (Sebastian et al, 2002;. In principle, an independent role of obesity in influencing the 24h-UpH may be of pathophysiological importance as the increased prevalence of kidney stones in obese subjects (Curhan et al, 1998;Borghi et al, 1999;Siener et al, 2004;Taylor et al, 2005b) could have been caused at least partly by an obesityrelated urine pH decrease (Maalouf et al, 2004). Kidney stones, especially idiopathic uric acid nephrolithiasis (Maalouf et al, 2004;Alvarez-Nemegyei et al, 2005), are usually associated with low urine pHs.…”

Section: Introductionmentioning

confidence: 99%

“…In principle, an independent role of obesity in influencing the 24h-UpH may be of pathophysiological importance as the increased prevalence of kidney stones in obese subjects (Curhan et al, 1998;Borghi et al, 1999;Siener et al, 2004;Taylor et al, 2005b) could have been caused at least partly by an obesityrelated urine pH decrease (Maalouf et al, 2004). Kidney stones, especially idiopathic uric acid nephrolithiasis (Maalouf et al, 2004;Alvarez-Nemegyei et al, 2005), are usually associated with low urine pHs. However, research on linkages between urinary pH and anthropometrics has so far been mainly conducted in patients with nephrolithiasis (Borghi et al, 1999;Maalouf et al, 2004;Siener et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Muscularity and adiposity in addition to net acid excretion as predictors of 24-h urinary pH in young adults and elderly

Berkemeyer

Rylander

Vormann³

2006

Eur J Clin Nutr

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Objective: In patients with nephrolithiasis, an inverse relationship between 24-h urinary pH (24h-UpH) and body weight has been reported. Whether body composition indices and 24h-UpH are similarly associated in healthy subjects needs investigation. Design: Cross-sectional, retrospective analysis. Setting: Dortmund, Germany and Gothenburg, Sweden. Subjects: Healthy young adults (18-23 years; n ¼ 117) and elderly (55-75years; n ¼ 85) having a mean body mass index (BMI) of 22.8073.4 and 25.373.9 kg/m 2 , respectively. Methods: Anthropometric data, 24h-UpH, and 24-h urinary excretion rates of net acid (NAE), creatinine, and urea were determined. After adjusting for urea (reflecting protein intake), renal creatinine output was used as a biochemical marker for muscularity. The BMI served as a marker of adiposity. Results: NAE, body weight, and BMI were significantly (Po0.05) higher, and height and creatinine significantly lower in the elderly, whereas body-surface area (BSA) was not different.Step-wise multiple regression analysis using BSA-corrected urinary variables revealed NAE as the primary predictor of 24h-UpH (with R 2 values of 0.64 and 0.68 in young adults and elderly, respectively, Po0.0001), followed by urea (Po0.0001), creatinine (Po0.05), and BMI (Po0.05 for the young adults and P ¼ 0.12 for the elderly). These associations were negative for NAE and BMI, and positive for urea and creatinine. Conclusions: Muscularity (i.e. creatinine adjusted for urea) and particularly in the group of young adults, adiposity (i.e. BMI) proved to be modest, but significant predictors of 24h-UpH. Future research should focus on more obese subjects in whom insulin resistance and particular kidney functions should also be examined to further substantiate the role of obesity in low-urine pH-associated conditions, for example, nephrolithiasis.

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Muscularity and adiposity in addition to net acid excretion as predictors of 24-h urinary pH in young adults and elderly

Berkemeyer

Rylander

Vormann³

2006

Eur J Clin Nutr

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Obesity, Weight Gain, and the Risk of Kidney Stones

Taylor

Stampfer²,

Curhan³

2005

JAMA

1,024

580

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Context Larger body size may result in increased urinary excretion of calcium, oxalate, and uric acid, thereby increasing the risk for calcium-containing kidney stones. It is unclear if obesity increases the risk of stone formation, and it is not known if weight gain influences risk.Objective To determine if weight, weight gain, body mass index (BMI), and waist circumference are associated with kidney stone formation. Design, Setting, and ParticipantsA prospective study of 3 large cohorts: the Health Professionals Follow-up Study (N=45988 men; age range at baseline, 40-75 years), the Nurses' Health Study I (N=93758 older women; age range at baseline, 34-59 years), and the Nurses' Health Study II (N=101877 younger women; age range at baseline, 27-44 years).Main Outcome Measures Incidence of symptomatic kidney stones. ResultsWe documented 4827 incident kidney stones over a combined 46 years of follow-up. After adjusting for age, dietary factors, fluid intake, and thiazide use, the relative risk (RR) for stone formation in men weighing more than 220 lb (100.0 kg) vs men less than 150 lb (68.2 kg) was 1.44 (95% confidence interval [CI], 1.11-1.86; P=.002 for trend). In older and younger women, RRs for these weight categories were 1.89 (95% CI, 1.52-2.36; PϽ.001 for trend) and 1.92 (95% CI, 1.59-2.31; PϽ.001 for trend), respectively. The RR in men who gained more than 35 lb (15.9 kg) since age 21 years vs men whose weight did not change was 1.39 (95% CI, 1.14-1.70; P=.001 for trend). Corresponding RRs for the same categories of weight gain since age 18 years in older and younger women were 1.70 (95% CI, 1.40-2.05; PϽ.001 for trend) and 1.82 (95% CI, 1.50-2.21; PϽ.001 for trend). Body mass index was associated with the risk of kidney stone formation: the RR for men with a BMI of 30 or greater vs those with a BMI of 21 to 22.9 was 1.33 (95% CI, 1.08-1.63; PϽ.001 for trend). Corresponding RRs for the same categories of BMI in older and younger women were 1.90 (95% CI, 1.61-2.25; PϽ.001 for trend) and 2.09 (95% CI, 1.77-2.48; PϽ.001 for trend). Waist circumference was also positively associated with risk in men (P=.002 for trend) and in older and younger women (PϽ.001 for trend for both). ConclusionsObesity and weight gain increase the risk of kidney stone formation. The magnitude of the increased risk may be greater in women than in men.

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Comparative Effectiveness of Shock Wave Lithotripsy and Ureteroscopy for Treating Patients With Kidney Stones

et al. 2014

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Association of urinary pH with body weight in nephrolithiasis

Abstract: We conclude that urinary pH is inversely related to body weight among patients with stones. The results confirm the previously proposed scheme that obesity may sometimes cause uric acid nephrolithiasis by producing excessively acid urine due to insulin resistance.

Cited by 353 publications

References 25 publications

Muscularity and adiposity in addition to net acid excretion as predictors of 24-h urinary pH in young adults and elderly

Muscularity and adiposity in addition to net acid excretion as predictors of 24-h urinary pH in young adults and elderly

Obesity, Weight Gain, and the Risk of Kidney Stones

Comparative Effectiveness of Shock Wave Lithotripsy and Ureteroscopy for Treating Patients With Kidney Stones

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