Dietary Risk Factors for Incident and Recurrent Symptomatic Kidney Stones.

OBJECTIVE: To compare dietary factors between incident symptomatic stone formers and controls, and among the incident stone formers, to determine whether dietary factors were predictive of symptomatic recurrence. PATIENTS AND METHODS: We prospectively recruited 411 local incident symptomatic kidney stone formers (medical record validated) and 384 controls who were seen at Mayo Clinic in Minnesota or Florida between January 1, 2009, and August 31, 2018. Dietary factors were based on a Viocare, Inc, food frequency questionnaire administered during a baseline in-person study visit. Logistic regression compared dietary risk factors between incident symptomatic stone formers and controls. Incident stone formers were followed up for validated symptomatic recurrence in the medical record. Cox proportional hazards models estimated risk of symptomatic recurrence with dietary factors. Analyses adjusted for fluid intake, energy intake, and nondietary risk factors. RESULTS: In fully adjusted analyses, lower dietary calcium, potassium, caffeine, phytate, and fluid intake were all associated with a higher odds of an incident symptomatic kidney stone. Among incident stone formers, 73 experienced symptomatic recurrence during a median 4.1 years of follow-up. Adjusting for body mass index, fluid intake, and energy intake, lower dietary calcium and lower potassium intake were predictive of symptomatic kidney stone recurrence. With further adjustment for nondietary risk factors, lower dietary calcium intake remained a predictor of recurrence, but lower potassium intake only remained a predictor of recurrence among those not taking thiazide diuretics or calcium supplements. CONCLUSION: Enriching diets in stone formers with foods high in calcium and potassium may help prevent recurrent symptomatic kidney stones.

Effects of denosumab on bone metabolism and bone mineral density in kidney transplant patients: a systematic review and meta-analysis.

OBJECTIVE: The use of immunosuppressive agents, especially glucocorticoids, are associated with increased risks of bone loss in kidney transplant patients. Denosumab, a potent antiresorptive agent, has been shown to increase bone mineral density (BMD) in patients with CKD. However, its effects on bone metabolism and BMD in kidney transplant patients remain unclear. METHODS: A literature search was conducted using MEDLINE, EMBASE, and Cochrane Database from inception through April 2018 to identify studies evaluating denosumab's effect on changes in bone metabolism and BMD from baseline to post-treatment course in kidney transplant patients. Study results were pooled and analyzed utilizing random-effects model. The protocol for this systematic review is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42018095055). RESULTS: Five studies (a clinical trial and four cohort studies) with a total of 162 kidney transplant patients were identified. The majority of patients had a baseline eGFR ≥ 30 mL/min/1.73 m2. After treatment (≥ 6 to 12 months), there were significant increases in BMD with standardized mean differences (SMDs) of 3.26 (95% CI 0.88-5.64) and 1.83 (95% CI 0.43 to 3.22) for lumbar spine and femoral neck, respectively. There were also significant increases in T scores with SMDs of 0.92 (95% CI 0.58 to 1.25) and 1.14 (95% CI 0.17 to 2.10) for lumbar spine and femoral neck, respectively. After treatment, there were no significant changes in serum calcium (Ca) or parathyroid hormone (PTH) from baseline to post-treatment course (≥ 6 months) with mean differences (MDs) of 0.52 (95% CI, - 0.13 to 1.16) mmol/L and - 13.24 (95% CI, - 43.85 to 17.37) ng/L, respectively. The clinical trial data demonstrated more asymptomatic hypocalcemia in the denosumab (12 episodes in 39 patients) than in the control (1 episode in 42 patients) group. From the cohort studies, the pooled incidence of hypocalcemia following denosumab treatment was 1.7% (95% CI 0.4 to 6.6%). All reported hypocalcemic episodes were mild and asymptomatic, but the majority of patients required Ca and vitamin D supplements. CONCLUSION: Among kidney transplant patients with good allograft function, denosumab effectively increases BMD and T scores in the lumbar spine and femur neck. From baseline to post-treatment, there are no differences in serum Ca and PTH. However, mild hypocalcemia can occur following denosumab treatment, requiring monitoring and titration of Ca and vitamin D supplements.

Impact of admission serum calcium levels on mortality in hospitalized patients.

OBJECTIVES: To assess the relationship between admission serum calcium levels and in-hospital mortality in all hospitalized patients. METHODS: All adult hospitalized patients who had admission serum calcium levels available between years 2009 and 2013 were enrolled. Admission serum calcium was categorized based on its distribution into six groups (<7.9, 7.9 to <8.4, 8.4 to <9.0, 9.0 to <9.6, 9.6 to <10.1, and ≥10.1 mg/dL). The odds ratio (OR) of in-hospital mortality by admission serum calcium, using the calcium category of 9.6-10.1 mg/dL as the reference group, was obtained by logistic regression analysis. RESULTS: 18,437 patients were studied. The lowest incidence of in-hospital mortality was associated with admission serum calcium within 9.6 to <10.1 mg/dL. A higher in-hospital mortality rate was observed in patients with serum calcium <9.6 and ≥10.1 mg/dL. Also, 38% and 33% of patients with admission serum calcium <7.9 and ≥10.1 mg/dL were on calcium supplements before admission, respectively. After adjusting for potential confounders, both serum calcium <8.4 and ≥10.1 mg/dL were associated with an increased risk of in-hospital mortality with ORs of 2.86 [95% confidence interval (CI) 1.98-4.17], 1.74 (95% CI 1.21-2.53), and 1.69 (95% CI 1.10-2.59) when serum calcium were within <7.9, 7.9 to <8.4, and ≥10.1 mg/dL, respectively. CONCLUSION: Hypocalcemia and hypercalcemia on admission were associated with in-hospital mortality. Highest mortality risk is observed in patients with admission hypocalcemia (<7.9 mg/dL). One-third of patients with hypercalcemia on admission were on calcium supplements.

Association between coffee consumption and risk of renal cell carcinoma: a meta-analysis.

BACKGROUND/OBJECTIVES: The risk of renal cell carcinoma (RCC) in individuals who regularly drink coffee is controversial. Several antioxidant compounds in coffee have been proposed to reduce the risk of RCC, while the findings from several studies raise concerns regarding a potential increased risk of RCC with coffee consumption. AIM: This meta-analysis aims to evaluate the association between coffee consumption and RCC. METHODS: A literature search was performed using MEDLINE, EMBASE and Cochrane Database of Systematic Reviews from inception until December 2016. Studies that reported odd ratios or hazard ratios comparing the risk of RCC in individuals who consumed a significant amount of coffee (at least one cup of coffee per day) versus those who did not consume coffee were included. Pooled risk ratios (RR) and 95% confidence intervals (CI) were computed using a random-effect, generic inverse variance method. RESULTS: Twenty-two observational studies (16 case-control and 6 cohort studies) were included in our analysis to assess the association between RCC and coffee consumption. The pooled RR of RCC in individuals consuming coffee was 0.99 (95% CI, 0.89-1.11). Subgroup analyses stratified by gender showed pooled RRs of RCC of 1.15 (95% CI, 0.85-1.55) in females and 0.87 (95% CI, 0.72-1.04) in males. CONCLUSIONS: Our study demonstrates no significant association between coffee consumption and RCC. Thus, coffee consumption is likely not a risk factor for RCC. Whether coffee consumption has a potential role in reduced risk of RCC, particularly in men, requires further investigations.

Association between mortality and replacement solution bicarbonate concentration in continuous renal replacement therapy: A propensity-matched cohort study.

BACKGROUND: Given the known deleterious effects seen with bicarbonate supplementation for acidemia, we hypothesized that utilizing high bicarbonate concentration replacement solution in continuous venovenous hemofiltration (CVVH) would be independently associated with higher mortality. METHODS: In a propensity score-matched historical cohort study conducted at a single tertiary care center from December 9, 2006, through December 31, 2009, a total of 287consecutive adult critically ill patients with Stage III acute kidney injury (AKI) requiring CVVH were enrolled. We excluded patients on maintenance dialysis, those who received other modalities of continuous renal replacement therapies, and patients that received a mixed of 22 and 32 mEq/L bicarbonate solution pre- and post-filter. The primary outcome was in-hospital and 90-day mortality rates. RESULTS: Among enrollees, 68 were used 32 mEq/L bicarbonate solution, and 219 received 22mEq/L bicarbonate solution for CVVH. Patients on 32 mEq/L bicarbonate solution were more often non-surgical, had lower pH and bicarbonate level but had higher blood potassium and phosphorus levels in comparison with those on 22 mEq/L bicarbonate solution. After adjustment for the baseline characteristics, the use of 32 bicarbonate solution was significantly associated with increased in-hospital (HR = 1.94; 95% CI 1.02-3.79) and 90-day mortality (HR = 1.50; 95% CI 1.03-2.14). There was a significant increase in the hospital (p = .03) and 90-day (p = .04) mortality between the 22 vs. 32 mEq/L bicarbonate solution groups following propensity matching. CONCLUSION: Our data showed there is a strong association between using high bicarbonate solution and mortality independent of severity of illness and comorbid conditions. These findings need to be evaluated further in prospective studies.

Coffee consumption and risk of nonalcoholic fatty liver disease: a systematic review and meta-analysis.

BACKGROUND/OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is a worldwide public health concern. Coffee might have a protective effect against NAFLD. However, the results of previous reports are conflicting. Therefore, we carried out this meta-analysis to summarize all available data. METHODS: This study consisted of two meta-analyses. The first meta-analysis included observational studies comparing the risk of NAFLD in patients who did and did not drink coffee. The second analysis included studies comparing the risk of liver fibrosis between NAFLD patients who did and did not drink coffee. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated. RESULTS: Out of 355 articles, five studies fulfilled our eligibility criteria and were included in the analysis. The risk of NAFLD in patients who drank coffee was significantly lower than that in patients who did not pooled RR 0.71 (95% CI, 0.60-0.85). We also found a significantly decreased risk of liver fibrosis among NAFLD patients who drank coffee compared with those who did not, with a pooled RR of 0.70 (95% CI, 0.60-0.82). However, it should be noted that the definition of regular coffee consumption varied between studies, which is the main limitation of this meta-analysis. CONCLUSION: Our study found a significantly decreased risk of NAFLD among coffee drinkers and significantly decreased risk of liver fibrosis among patients with NAFLD who drank coffee on a regular basis. Whether consumption of coffee could be considered a preventative measure against NAFLD needs further investigations.

Association of coffee consumption and chronic kidney disease: A meta-analysis.

BACKGROUND/OBJECTIVES: The risk of chronic kidney disease (CKD) in individuals who regularly drink coffee is controversial. The aim of this meta-analysis was to evaluate the association between coffee consumption and CKD. METHODS: A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception until April 2016. We included studies that reported odd ratios or hazard ratios comparing the risk of CKD in individuals consuming significant amount of coffee vs. those who did not consume coffee. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. RESULTS: Four observational studies with 14 898 individuals were included in our analysis to assess the association between coffee consumption and CKD. Coffee consumption was defined as one cup of coffee per day or greater. The pooled RR of CKD in individuals consuming coffee was 0.71 (95% CI, 0.47-1.08). The subgroup analysis showed the pooled RRs of CKD of 1.10 (95% CI, 0.94-1.29) in males and 0.81 (95% CI, 0.58-1.13) in females, respectively. CONCLUSIONS: Our study demonstrates no significant association between coffee consumption and CKD in males. However, future studies are required to assess a potential inverse association between coffee consumption and risk for developing CKD in females.

Dysmagnesemia in Hospitalized Patients: Prevalence and Prognostic Importance.

OBJECTIVE: To examine the prevalence of serum magnesium (Mg) alterations and outcomes in hospitalized patients. PATIENTS AND METHODS: All admissions to Mayo Clinic in Rochester, Minnesota, from January 1, 2009, through December 31, 2013 (288,120 patients), were screened. Admission Mg from each unique patient and relevant clinical data were extracted from the institutional electronic database. RESULTS: After excluding patients aged less than 18 years, those without Mg measurement, and readmission episodes, a total of 65,974 patients were studied. Magnesium levels of 2.1 mg/dL or higher were found in 20,777 patients (31.5%), and levels less than 1.7 mg/dL were noted in 13,320 (20.2%). Hypomagnesemia was common in patients with hematologic/oncological disorders, and hypermagnesemia was common in those with cardiovascular disease. The lowest hospital mortality, assessed by restricted cubic spline and percentage death, occurred in patients with Mg levels between 1.7 and 1.89 mg/dL. An Mg level of less than 1.7 mg/dL was independently associated with an increased risk of hospital mortality after adjusting for all variables except the admission diagnosis; risk for longer hospital stay and being discharged to a care facility were increased in the fully adjusted model. An elevated Mg level of 2.3 mg/dL or higher was a predictor for all adverse outcomes. The magnitude of Mg elevations in patients with levels of 2.3 mg/dL or higher (N=7908) was associated with worse hospital mortality in a dose-response manner. In patients with cardiovascular diseases, Mg levels of 1.5 to 1.69 mg/dL and 2.3 mg/dL or higher both independently predicted poor outcomes including hospital mortality. CONCLUSION: Dysmagnesemia in hospitalized patients is common, with hypermagnesemia being most prevalent. Compared with hypomagnesemia, hypermagnesemia is a stronger predictor for poor outcomes. Magnesium supplementation for patients without Mg deficiency should be avoided in the absence of randomized controlled trials documenting a benefit.