| Abstract|| |
Saudi Arabia has extremely hot climate for most of the year; this is associated with the risk of developing nephrolithiasis. This retrospective research aimed to investigate the current prevalence, manifestation, mode of treatment, and risk factors of renal stones in Jeddah and Riyadh, Saudi Arabia. A cross-sectional study was conducted from November 2018 to June 2019 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. This study included 1031 participants aged ≥18 years from Jeddah (n=652, 63.3%) and Riyadh (n=379, 36.8%). Data were expressed as mean ± standard deviation (minimum-maximum) or number (%). Comparisons between patients with and without renal stones were made using the Chi-square test and unpaired Student’s t-test as appropriate. The odds ratio (OR) with a 95% confidence interval (95% CI) was determined for the risk factors of renal stones. The prevalence of renal stones was 16.9% among the participants. A significantly high risk for renal stones was associated with male sex (2.96; 95% CI: 2.08–4.20, P = 0.0001) and age group of 34–40 years (OR: 1.44; 95% CI: 1.005–2.103, P = 0.047). Hypertension was more common in patients with renal stones than those without renal stones (9.5% vs.4.6%, P = 0.013). The percentage of patients who took diuretics was significantly higher among those with renal stones than among those without renal stones (11.2% vs. 3.5%, P = 0.001). Of the 169 patients with renal stones, 58.0% had a positive family history of renal stones, and 23.7% had a history of urinary tract infections (UTIs). The symptoms of renal stones were pain (86.4%), hematuria (11.2%), fever (2.4%), and others (0.6%). Of all the patients, 43.8% took medication. For most patients, the stones passed spontaneously (67.5%), while 23.7% underwent lithotripsy, and 1.5% received stents. In this study, we found a higher prevalence of renal stones two major cities in Saudi Arabia in Jeddah and Riyadh, at 16.4%. Risk factors included male sex and age group of 34–40 years. A significant number of patients with renal stones have a family history of renal stones and a history of UTI. Loin pain and hematuria were the two major clinical presenting symptoms for renal stones. In the majority of patients, the renal stones passed spontaneously without the need for lithotripsy or surgery.
|How to cite this article:|
Safdar OY, Alblowi SS, Aboulola NA, Alharazy DT. Renal Stones and Risk Factors in Jeddah and Riyadh. Saudi J Kidney Dis Transpl 2021;32:191-8
|How to cite this URL:|
Safdar OY, Alblowi SS, Aboulola NA, Alharazy DT. Renal Stones and Risk Factors in Jeddah and Riyadh. Saudi J Kidney Dis Transpl [serial online] 2021 [cited 2021 Sep 18];32:191-8. Available from: https://www.sjkdt.org/text.asp?2021/32/1/191/318523
| Introduction|| |
Renal stone (nephrolithiasis) is a common disease, which is becoming widespread worldwide. It is common in developed and Industrialized countries, where its lifetime prevalence is approximately 14.0%, and this rate has been increasing. The lifetime risk of renal stones is 1.0%–5.0% in Asia, 5.0%–9.0% in Europe, and 10.0%–15.0% in the USA. Furthermore, it is a common disease in Saudi Arabia. Recent studies have shown that the prevalence of renal stones is as high as 20.0% among Saudi Arabians. Since it is a chronic and recurring health condition, its management involves a high burden of direct and indirect costs on patients.
There is a higher prevalence of renal stones in individuals living in areas with hot climate compared to areas with moderate climate. Decreased fluid intake, increased perspiration, and increased urinary concentration predispose to increased crystallization and stone formation. Besides climatic conditions, there are other risk factors for stone formation, such as genetic factors, race, sex, age, socio-economic profiles, occupation, and body weight.
Patients with renal stone are usually asymptomatic. However, symptoms of renal stones may include hematuria, dysuria, loin pain, urinary tract obstruction, or urinary tract infection (UTI). The patient may also present with restlessness, sweating, pallor, and vomiting. Treatment of renal stones may be medical or surgical. The treatment choice varies according to the patient, renal stone type and size, and location of the renal stone. Treatment options include oral stone dissolution, extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and open or laparoscopic lithotomy.
The aim of this retrospective study was to determine the prevalence, manifestations, treatment, and risk factors of renal stones in patients in Jeddah and Riyadh. Determining the risk factors specifically for our population allows for better health service that is designed to target the community’s risk factors to help reduce the prevalence of renal stones. Knowing the most common manifestations specific to our patients helps in earlier diagnosis of renal stones.
| Patients and Methods|| |
A noninterventional cross-sectional community-based survey was conducted from November 2018 to June 2019 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Ethical approval was obtained from the Unit of Biomedical Ethics Research Committee at King Abdulaziz University, Jeddah, Saudi Arabia (Reference No 264-19). The participants’ consent for participation in the study was obtained through questionnaires. They were informed regarding the type of study being conducted, and all responses were confidential. A simple random sampling method was used to determine the sample size. The questionnaire was distributed via social media to participants from Jeddah and Riyadh. The participants were asked to read and answer the questions carefully. This study included 1031 participants aged ≥18 years from Jeddah (n= 652) and Riyadh (n= 379).
The questionnaire was composed of two parts: the first part comprised questions about the sociodemographic characteristics of the participants, such as the city of residence, sex, age, body mass index, education level, presence of chronic illnesses, and medication intake. The second part elicited information with regard to renal stones, such as the positive family history of renal stones, symptoms of renal stones, history of UTI, and medications and treatment of renal stones.
| Statistical Analysis|| |
Data analysis was done using IBM SPSS Statistics version 20.0 (IBM Corp., Armonk, NY, USA) and MedCalc software. The data extracted were coded, crosschecked, and entered on a daily basis. Data were expressed as mean ± standard deviation (minimum-maximum) or number (%). Comparisons between patients with and without renal stones were made using the Chi-square test and unpaired Student’st-test as appropriate. Odds ratio (OR) with a 95% confidence interval (95% CI) was determined for the risk factors of renal stones using MedCalc software; a P<0.05 was considered significant.
| Results|| |
[Table 1] shows the demographic characteristics of the participants from Jeddah (63.2%) and Riyadh (36.8%). There were insignificant differences between the patients from Jeddah and Riyadh with renal stones (66.9% vs.62.5%) compared to those without renal stones (33.1% vs.37.5%, P=0.163). The number of females with renal stones was significantly higher than the males (59.2% versus 40.8%, P=0.0001) because there were more female participants (77.5%) than male participants (22.5%). The patients who had renal stones were mostly from the age group of 18–30 years (33.70%), followed by 34–40 years (29.0%), 41–50 years (14.2%), and lastly, >50 years (14.20%), with a significant difference between age groups (P=0.032). The weight and height of patients with renal stones were significantly higher than those of individuals without renal stones (P=0.006 and P=0.012). Regarding education levels, most of the patients with and without renal stones had graduate degrees (58.60% and 65.7%), followed by post-graduate degrees (20.7% and 15.9%), high school (15.4% and 16.4%), illiterate (4.10% and 0.3%), and lastly, middle school (1.2% and 1.7%), with a significant difference between groups (P=0.0001). Most patients with and without renal stones did not have chronic diseases (76.3% and 83.2%, respectively); however, among patients with chronic disease, there was a significant difference in the number of patients with and without renal stones (23.7% and 16.8%, respectively; P=0.024). The chronic diseases in all participants were hypertension (5.4%), type 1 diabetes mellitus (T1DM; 2.5%), type 2 diabetes mellitus (T2DM; 3.7%), and others (7.0%). Hypertension was observed more frequently in participants with renal stones than in those without renal stones (9.5% vs.4.6%, P=0.013). Among these participants with hypertension, 11.0% of patients took medications. Patients who used diuretics had more renal stones than those who did not use diuretics (11.2% vs.3.5%, P=0.001).
|Table 1: Comparison of demographic characteristics of patients with and without kidney stones.|
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[Table 2] shows the characteristics of patients with renal stones. Out of 169 patients with renal stones, 58.0% had a positive family history, and 23.7% had a history of UTI. The symptoms of renal stones were mostly pain (86.4%), hematuria (11.2%), fever (2.4%), and other symptoms (0.6%). Of all the patients who participated in our study, 43.8% took the medication as a treatment for renal stones. In most patients, the stones passed spontaneously (67.5%), while 23.7% underwent lithotripsy, and 1.5% received stents.
Risk factors for renal stones are listed in [Table 3]. Significant high risk for renal stones was found for male sex (OR: 2.96; 95% CI: 2.08–4.20, P=0.0001) and the age group of 34–40 years (OR: 1.44; 95% CI: 1.005–2.103, P=0.047) and obesity.
| Discussion|| |
In this study, the prevalence of renal stones in Jeddah and Riyadh was 16.40%. This prevalence was slightly higher than the reported value of 12.3% in ArAr city, Saudi Arabia.
The common risk factors for the occurrence of renal stones are age, sex, weather, season, stress, water intake, nature of the patient’s job, diet, genetics, and metabolic changes.
The results of this study showed that the number of females who had renal stones was significantly higher than that of males. This may be because this study had more female participants. However, statistical analyses showed that the male sex had a higher risk for developing renal stones compared to the female sex (OR 2.95, 95% CI 2.08–4.20), and that being a female is a protective factor (OR 0.338, 95% CI 0.238–0.480). Given this, others have reported that urinary calculi were more common in men as compared to women, with a ratio of 2.4:1. In Italy, another study was conducted among 1543 subjects, with a male-to-female ratio of 0.79. The overall prevalence of renal stone disease (currently or previously) was 7.5%; the prevalence of the disease in males was higher than that in females (8.5 vs. 6.6%). Previous research has shown that stones are twice or thrice more common in males than in females; however, recent data indicated that this disparity is dwindling. Phosphate and magnesium levels in urine are higher in males than in females, which decreases the concentration of urinary citrates. This is due to a higher dietary intake of protein in men, making them more prone to renal stones. In contrast, females produce copious amounts of citric acid because of estrogen, which is protective against renal stones.,
The participants in this study were above 18 years of age. The prevalence of renal stones reported in this study was the highest in the age group 18–30 years, followed by 34–40 years (29.00%), 41–50 years (23.10%), and lastly, >50 years (14.20%). The age group of 34–40 years has a high risk for renal stones (OR: 1.454, 95% CI: 1.005–2.103), while the age group of 18–30 years showed a protective effect against stone formation (OR: 0.605, 95% CI: 0.428–0.854). Regarding the factor of age, we noted a pattern where the highest frequency of developing renal stones was when the patient was at the peak of his or her career; this confirms the hypothesis that dietary habits and lifestyle could be risk factors for renal stones.
Aside from the many health consequences associated with obesity, a rise in the prevalence of urinary stones is expected. In this study, the body weight and height were significantly higher in patients with renal stones than in healthy participants. The weights of the patients with renal stones were as follows: normal weight (39.60%), overweight (34.9%), obese (22.5%), and underweight (3.0%). With respect to this, a 2017 study on a Mediterranean population did not confirm obesity as a risk factor for renal stones. This may be because of the low quantity of acidic food in the Mediterranean diet; renal stones are more likely to form when there is a higher acid load in the diet. In contrast, various cohort studies showed that obesity in patients increases the risk for developing nephrolithiasis, and higher levels of visceral adiposity are associated with uric acid nephrolithiasis. The National Health and Nutrition Examination Survey retrospective study revealed that renal stone diseases were more likely in obese individuals (11.2%, 95% CI 10.0–12.3%) as compared to normal-weight individuals (6.1%, 95% CI 4.8–7.4%, P<0.001).
In this study, 58% of the participants with renal stones had a positive family history. The importance of taking a family history in the nephrology clinic was discussed previously. It is well known that some types of renal stones are familial. A study that featured twins showed that heritability of renal stones was approximately 56%, and this has been supported by many studies that assessed the familial pattern of renal stones. Research in the field of familial renal stones is limited, with genetics (usually within a single gene) and genomic factors (within an individual’s entire DNA sequence) being studied less commonly due to their complexity. Lately, there has been meticulous research regarding causes of rare monogenetic renal stones in selected stone-forming populations., Some authors have reported that genetic mutations in the human CaSR gene are associated with a high susceptibility for hypercalciuria, which is a known risk factor for calcium renal stones. This finding can be attributed to the positive family history in many patients with renal stones. However, stone formation in a patient may not always indicate that developing renal stones is a completely familial disease. Family members do not share the same genes or lifestyle and dietary habits. The abnormal frequency of stones in the same families may be explained as a hereditary tendency to develop kidney stones, and it is only observed when some of the lifestyle and dietary habits are similar. Missed diagnoses of familial nephrolithiasis could cause substandard medical management, development of life-threatening complications, such as end-stage renal failure, and lack of screening of other family members.
In this study, 23.7% of the patients with renal stones had chronic diseases, such as hypertension (9.5%), T1DM (3.0%), T2DM (5.9%), and others (7.1%). Hypertension was observed more in individuals with kidney stones than in healthy participants (9.5% versus 4.9%). With respect to this, a study compared the results of a 24-h urinalysis in individuals with high blood pressure and normal individuals; it showed that individuals with high blood pressure excreted less citrate than normal individuals. Citrate protects against formation of renal stones; hence, a decrease in the excretion of citrate might have contributed to the greater rates of kidney stones in hypertensive patients., Japanese studies showed that hypertension was an independent risk factor for renal stones, regardless of sex, age, and other metabolic syndrome components. Those with hypertension are more likely to develop renal stones, especially when they are over-weight. Poor glycemic control and insulin resistance increase the risk for forming renal stones., In a retrospective study from 2008 to 2015, diabetes was significantly related to the risk of developing calcium stones. Patients with poor glycemic control have been found to have higher levels of calcium, oxalate, and uric acid in the urine, which leads to a decrease in ammonia and citrate excretion and urinary acidification. These findings all lead to a higher likelihood for the development of renal stones. The limitation of the study was that it included two cities only, and it is a cross-sectional study. A prospective follow-up study is recommended to further investigate possible causation.
In this study, we found a higher prevalence of renal stones two major cities in Saudi Arabia in Jeddah and Riyadh, at 16.40%. The risk factors for developing renal stones sex, age group of 34–40 years, positive family history, and associated diseases, such as hypertension and UTI, obesity, and overweight play a major role in the development of urinary stones in the Saudi population. Loin pain and hematuria were the two major clinical presenting symptoms for renal stones. In the majority of patients, the renal stones passed spontaneously without the need for lithotripsy or surgery. This study may improve knowledge on the risk factors of renal stones, which may help in reducing its prevalence by spreading awareness regarding the most common causes that are specific to people from Jeddah and Riyadh. Further, raising awareness through health education may lead to a decrease in the development of urinary stones in Saudi Arabia.
Conflict of interest: None declared.
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Shahd S Alblowi
Faculty of Medicine, King Abdulaziz University, P. O. Box: 14071, Jeddah
[Table 1], [Table 2], [Table 3]