Does Milk Intake Play a Specific Role in the Pathogenesis of Kidney Stones?

Abstract

026specifying the type). In addition, the variables collected for each patient and control provide demographic data (gender, age, height and weight) and information on the type of stones and the number of episodes of colic up to completion of the questionnaire (patients only) (Tables 1,2). Although the type of the kidney stones was not known in all the patients, most of the calculi analysed were calcium oxalate kidney stones, like observed in the general population (Table 1). Statistical analysisDescriptive analysis was performed for each variable, including frequency distribution of the variables and calculation of the elementary statistics (mean, standard deviation, minimum and maximum) for the quantitative variables in patients and controls. Distribution was determined using Chi-square tests. Student's t-test was used to assess quantitative variables. Thereafter, logistic regression analysis was performed to assess the importance of each factor on the probability of being patients or controls. In addition to food intake, BMI (calculated on weight and height and split into ≤25 or >25 kg/m 2 ), age (≤50 years or >50 years) and gender were taken into consideration. A backwards variable selection method was adopted where p<0.05 (Wald's test) was minimum threshold. The odds ratio and 95% confidence limits were calculated for the other variables present in the final model. All the analysis was performed using SAS V8.2 software for Windows. ResultsFrequency distributions and elementary statistics carried out to better assess the extent of the differences observed revealed that IntroductionDiet plays a key role in the pathogenesis of kidney stones [1]. In particular, recent findings have advanced knowledge on the protective role of a high calcium diet in the pathophysiology of the formation of calcium oxalate stones (the most common variety). Nonetheless, not much is known about the specific action of different foods supplying calcium, in particular the specific role played by milk intake, compared with other dairy products (mainly cheese) in kidney stone formation. We performed a retroactive case-controlled study using a questionnaire to investigate the eating pattern of patients presenting kidney stones in our territory, and also to assess the role of milk intake and various dietary alimentary factors. Subjects and Methods Study populationOur study cohort was made up of 42 patients (21 males and 13 females) attending our lithotripsy centre and 20 healthy controls (6 males and 14 females) with no history of kidney stones. Neither taking vitamin D or calcium from non-dairy sources. Assessment of dietary and non dietary variablesThe entire study cohort was given a semi-quantitative questionnaire (using standard household units of weight to make the form userfriendly) to reveal the frequency and customary mean daily intake of meat (without specifying the type), salt, cheese (without specifying the type), milk (without specifying the type), pasta (without specifying the type), sugar (without specifying the type), vegeta...

Kidney stones and dietary intake in adults: a population-based study in southwest Iran

“…In line with our results, one study found that consuming dairy is associated with a reduced risk of kidney stones [ 22 ]. However, increased milk intake is recommended for uric acid-related stones [ 23 ]. Therefore, policies that promote a diet high in dietary alkali load can help reduce the risk of kidney stone formation.…”