Adherence to Mediterranean Diet, Dietary Salt Intake, and Susceptibility to Nephrolithiasis: A Case-Control Study.

Unhealthy dietary habits play a key role in the pathogenesis of nephrolithiasis (NL). The aims of this case-control study were to evaluate (i) the adherence to the Mediterranean Diet (MD) and the dietary salt intake in stone-forming patients (SF), (ii) the relationship occurring between MD adherence, salt intake and NL-related metabolic risk factors in SF, and (iii) the impact of combined high MD adherence and low salt intake on NL susceptibility. From 1 January 2018 to 31 December 2019, we recruited all SF consecutively referred to the Extracorporeal Shock Wave Lithotripsy (ESWL) center of Federico II University, and at least two control subjects without a personal history of NL, age-, sex-, and body mass index-matched to SF (NSF). All study participants were interviewed using the validated MEDI-LITE and MINISAL questionnaires. In an SF subgroup, the NL-related metabolic risk factors were also evaluated. SF showed a lower MD adherence and a higher salt intake compared with NSF. The NL susceptibility decreased by 36% [OR: 0.64 (0.59-0.70); p < 0.01] for each point of increase in MEDI-LITE score, while it increased by 13% [OR: 1.13 (1.03-1.25); p = 0.01] for each point of increase in MINISAL score. The SF prevalence was higher among subjects showing combined low MD adherence and high salt intake. In SF, the MEDI-LITE score directly correlated with 24 h-citraturia, whereas the MINISAL score directly correlated with urinary sodium and uric acid excretion. In conclusion, high MD adherence and low salt intake are associated with a reduced NL susceptibility, both separately and in combination.

Venous thromboembolism and major bleeding in severe and critical COVID-19 hospitalized patients.

Venous thromboembolism (VTE) and major bleeding (MB) are life-threatening complications described in COVID-19 hospitalized patients and they can be considered as two sides of the same coin. This retrospective study aims to evaluate the risk factors for VTE and MB in COVID-19 patients admitted to two Italian hospitals. The medical records of all COVID-19 patients (males 139; 62.3%, mean age 67.2±13.6 years, body weight 88.2±20.6 kg) hospitalized from March 11th to July 31st, 2020 to the Federico II University Hospital and to Sea Hospital, Naples, Italy, were analyzed. The COVID-19 patients were classified into four groups: COVID-19 patients developing VTE and/or MB, COVID-19 patients developing only VTE, COVID-19 patients developing only MB, and COVID-19 patients not developing neither VTE nor MB. During the hospitalization, 53 COVID-19 patients (24.7%; males 40; 75.5%, mean age 67.2±13.6 years, weight 88.2±20.6 kg) developed VTE, 33 COVID-19 patients (15.3 %; males 17; 51.5, mean age 67.3±14.9 years, weight 74.1±14.3 kg) developed MB, and 129 COVID-19 patients not developed neither TVP nor MB. No parameters to identify severe COVID-19 complicated by VTE and/or MB were found. However, some clinical and biochemical parameters can be evaluated to predict the risk of MB in order to modify the treatment and take prompt action to reduce mortality.

Vitamin D Status, Cardiovascular Risk Profile, and miRNA-21 Levels in Hypertensive Patients: Results of the HYPODD Study.

The vitamin D and microRNA (miR) systems may play a role in the pathogenesis of cardiometabolic disorders, including hypertension. The HYPODD study was a double-blind placebo-controlled trial aiming to assess the effects of cholecalciferol treatment in patients with well-controlled hypertension and hypovitaminosis D (25OHD levels < 50 nmol/L). In addition to this clinical trial, we also evaluated the effects of cholecalciferol and calcitriol treatment on miR-21 expression in vivo and in vitro, respectively. Changes in the cardiovascular risk profiles were evaluated in HYPODD patients treated with cholecalciferol (C-cohort) or with placebo (P-cohort). The miR-21circulating levels were measured in four C-cohort patients and five P-cohort patients. In vitro, the miR-21 levels were measured in HEK-293 cells treated with calcitriol or with ethanol vehicle control. Cholecalciferol treatment increased 25OHD levels and reduced parathormone, total cholesterol, and low-density lipoprotein cholesterol levels in C-cohort patients, whereas no significant changes in these parameters were observed in P-cohort patients. The miR-21 circulating levels did not change in the C- or the P-cohort patients upon treatment. Calcitriol treatment did not affect miR-21 levels in HEK-293 cells. In conclusion, hypovitaminosis D correction ameliorated the cardiovascular risk profiles in hypertensive patients treated with cholecalciferol but did not influence the miR-21 expression.

Spontaneous Muscle Hematoma in Patients with COVID-19: A Systematic Literature Review with Description of an Additional Case Series.

Coagulation abnormalities, thrombosis, and endothelial dysfunction have been described in COVID-19 patients. Spontaneous muscle hematoma (SMH) is a rare complication in COVID-19. The aims of this study are to: (1) perform a systematic review of the literature to better define the clinical SMH characteristics, (2) describe the prevalence and the clinical characteristics of SMH in COVID-19 patients referring to a Department of Internal Medicine (IM) (Federico II University of Naples), a Department of Sub-Intensive Care Medicine (SIM) (Ospedale Del Mare), and a Department of Intensive Care Unit (ICU) (Federico II University). The systematic review was performed according to PRISMA criteria. The local prevalence of SMH in COVID-19 was evaluated retrospectively. The medical records of all COVID-19 patients referring to IM and ICU from March 11th, 2020, to February 28th, 2021 were examined for SMH occurrence. In our retrospective analysis, we describe 10 cases of COVID-19 patients with SMH not previously reported in literature, with a prevalence of 2.1%. The literature review, inclusive of our case series, describes a total of 50 SMHs in COVID-19 patients (57.4% males; mean age 68.8 ± 10.0 years). The SMH sites were ileo-psoas, vastus intermedius, gluteus, sternocleidomastoid, and pectoralis major muscles. Males developed SMH earlier than females (9.5 ± 7.8 vs. 17.1 ± 9.7 days). Ileo-psoas hematoma was more frequent in males (69.2 vs. 30.8%), while pectoralis major hematoma occurred only in females. The in-hospital mortality rate of SMH in COVID-19 patients was 32.4%. SMH is a rare but severe complication in COVID-19 hospitalized patients, associated with high mortality. A gender difference seems to be present in the clinical presentation of the disorder.

Calcium daily intake and the efficacy of a training intervention on optimizing calcium supplementation therapy: A clinical audit.

BACKGROUND AND AIMS: Calcium is an essential element for human health, with key roles in the prevention and therapy of multifactorial conditions. Calcium dietary intake is often insufficient in the general population. The aim of this study was to perform a clinical audit for general practitioners (GPs) to understand the efficacy of training intervention on doctors' awareness about dietary calcium and supplements. METHODS AND RESULTS: General practice outpatients were enrolled (Before Clinical Audit, BCA) from the same sanitary district, and calcium dietary intake was evaluated with a validated questionnaire, also collecting information about the consumption of calcium and vitamin D supplements. Then, a training intervention with a frontal lesson and discussion with GPs involved was performed. After one month of this intervention, a second outpatient enrolment was performed (Post Clinical Audit, PCA) in the same general practices to evaluate differences in nutritional suggestions and supplement prescription by GPs. In BCA, the calcium dietary intake was low, with nobody reaching 1000 mg as suggested by the guidelines. Only 6.6% and 24.5% took calcium and vitamin D supplements, respectively; in the PCA, these percentages increased to 28% and 78% for calcium and vitamin D supplements, respectively (p < 0.01 PCA vs BCA). There were no differences in calcium dietary intake between BCA and PCA. CONCLUSION: Training intervention on GPs was successful to sensitize them regarding calcium intake problems; GPs tended to increase the prescription of supplements but not to suggest changes in dietary habits.

Preventive Role of Vitamin D Supplementation for Acute Phase Reaction after Bisphosphonate Infusion in Paget's Disease.

CONTEXT: Intravenous aminobisphosphonates (N-BPs) can induce an acute phase reaction (APR) in up to 40% to 70% of first infusions, causing discomfort and often requiring intervention with analgesics or antipyretics. OBJECTIVE: Our aim was to explore the risk factors of APR in a large sample of patients with Paget's disease of bone (PDB) and to assess the possible preventive effects of vitamin D administration. METHODS: An observational analysis was performed in 330 patients with PDB at the time of N-BP infusion. Then, an interventional study was performed in 66 patients with active, untreated PDB to evaluate if vitamin D administration (oral cholecalciferol 50 000 IU/weekly for 8 weeks before infusion) may prevent APR. RESULTS: In a retrospective study, APR occurred in 47.6% and 18.3% of naive or previously treated patients, respectively. Its prevalence progressively increased in relation to the severity of vitamin D deficiency, reaching 80.0% in patients with 25-hydroxyvitamin D (25OHD) levels below 10 ng/mL (relative risk (RR) = 3.7; 95% confidence interval (CI) 2.8-4.7, P < .0001), even in cases previously treated with N-BPs. Moreover, APR occurred more frequently in patients who experienced a previous APR (RR = 2.8; 95% CI 1.5-5.2; P < .001) or in carriers of SQSTM1 mutation (RR = 2.3; 95% CI 1.3-4.2; P = .005). In the interventional study, vitamin D supplementation prevented APR in most cases, equivalent to a RR of 0.31 (95% CI 0.14-0.67; P < .005) with respect to prevalence rates of the observational cohort. A similar trend was observed concerning the occurrence of hypocalcemia. CONCLUSIONS: The achievement of adequate 25OHD levels is recommended before N-BP infusion in order to minimize the risk of APR or hypocalcemia in PDB.

Interleukin-6 trans-signaling and pathological low back pain in patients with Paget disease of bone.

The interleukin (IL)-6 biological system plays a key role in the pathogenesis of Paget disease (PD) of bone and pathological bone pain. Bone pain, particularly in the lower back region, is the most frequent symptom in patients with PD. This case-control study aimed to evaluate the relationship between the IL-6 system and low back pain (LBP) in patients with PD. We evaluated 85 patients with PD, with the disease localized in the lumbar spine, pelvis, and/or sacrum, and classified them based on the presence or absence of LBP, before and after aminobisphosphonate treatment. We also examined 32 healthy controls without LBP. Before treatment, IL-6 levels in patients with PD were higher than those in the controls, without difference between patients with or without LBP. Patients with PD with LBP (35/85) showed higher IL-6-soluble receptor (sIL-6R) and lower soluble glycoprotein (sgp) 130 levels compared with both patients with PD without LBP and controls (sIL-6R: 46.9 ± 7.4 vs 35.4 ± 8.6 vs 29.9 ± 4.2 ng/mL; sgp130: 307.2 ± 35.4 vs 341.4 ± 41.4 vs 417.1 ± 58.5 ng/mL, respectively). Paget disease remission, 6 months after treatment, is associated with LBP improvement. This phenomenon is associated with reduced sIL-6R levels and increased sgp130 levels in patients with PD with LBP at the baseline. Considering the biological properties of IL-6, sIL-6R, and sgp130, the results of the study suggest that the perception of LBP in patients with PD could be linked to an enhanced transmission of IL-6 signal in the specialized neural system activated by nociceptors.

Risk factors for silent myocardial ischemia in patients with well-controlled essential hypertension.

Silent myocardial ischemia (SMI) is frequently observed in patients with essential hypertension (EH). The major risk factor for SMI is uncontrolled blood pressure (BP), but SMI is also observed in patients with well-controlled BP. To evaluate the prevalence of SMI and the factors associated with SMI in EH patients with well-controlled BP. The medical records of 859 EH patients who underwent simultaneous 24-h ambulatory blood pressure monitoring (ABPM) and 24-h ambulatory electrocardiogram recording (AECG) were retrospectively evaluated. Each SMI episode was characterized by: (a) ST segment depression ≥0.5 mm; (b) duration of ST segment depression >60 s; and (c) reversibility of the ST segment depression. Overall 126 EH patients (14.7 %) had at least one episode of SMI. The SMI events were more frequent among patients with poorly controlled compared to those with well-controlled BP [86/479 (17.95 %) vs. 40/380 (10.52 %), p < 0.01]. Among EH patients with well-controlled BP, current and past smoking as well as the presence of an additional metabolic syndrome (MetS) constitutive element (obesity, impaired fasting glucose level or dyslipidemia) were significantly associated with the occurrence of SMI. In all EH patients with well-controlled BP and AECG evidence of SMI, there were one or more coronary artery stenotic lesions greater than 50 % found at coronary angiography. In EH patients who are current smokers, or have one or more additional components of a MetS there is markedly reduced benefit associated with good BP control with regard to the occurrence of myocardial ischemia: in this patient category, an AECG may help detect this condition.

Evidence for epistatic interaction between VDR and SLC13A2 genes in the pathogenesis of hypocitraturia in recurrent calcium oxalate stone formers.

BACKGROUND: Genetic factors play a key role in the pathogenesis of hypocitraturia, a common risk factor for nephrolithiasis. The Na+-dicarboxylate cotransporter NaDC1, encoded by the sodium-dicarboxylate cotransporter (SLC13A2) gene, is a major determinant of urinary citrate excretion and its biological functions are regulated also by the vitamin D/Vitamin D receptor (VDR) biological system. The aim of this case-control study was to evaluate the possible epistatic interaction between VDR rs731236and SLC13A2 rs11567842 allelic variants in the pathogenesis of hypocitraturia. METHODS: Recurrent calcium-oxalate stone formers (SF) with or without hypocitraturia and healthy controls (C) were genotyped. Gene-gene interactions were estimated by the 1.0 software package of multifactor dimensionality reduction (MDR). RESULTS: The prevalence of VDR TT and SLC13A2 GG genotypes was higher in hypocitraturic SF compared to C (odds ratio [OR] 3.24, 95 % confidence interval [CI] 1.38-7.60 for VDR TT vs. VDR tt and OR 4.06, 95 % CI 1.75-9.42 for SLC13A2 GG vs. SLC13A2 AA ). MDR analysis indicated a significant interaction between VDR TT and SLC13A2 GG in hypocitraturic SF compared to C [OR 3.81 (2.11-6.88)]. These data are compatible with an epistatic interaction between the VDR TT and SLC13A2 GG genotypes with a significant impact on the magnitude of the effect (suppressive effect). CONCLUSIONS: These results point to an epistatic interaction between the VDR and the SLC13A2 alleles in the pathogenesis of idiopathic hypocitraturia in calcium-oxalate SF.

Left ventricular diastolic dysfunction in type I Gaucher disease: an echo Doppler study.

Type I Gaucher disease (GD1) is an autosomal recessive lysosomal storage disease characterized by multiorgan damage. Left ventricular (LV) involvement has been rarely reported. Accordingly, the aim of the study was to evaluate LV geometry and function in a series of patients with GD1. Eighteen patients with GD1, 18 age- and sex-matched normal controls, and 18 age- and sex-matched hypertensive patients (HTN) were compared by standard echo Doppler examination. LV mass index, relative wall thickness and ejection fraction, transmitral E/A ratio, E velocity deceleration time (DT), atrial filling fraction (AFF = time-velocity integral of A velocity/time-velocity integral of total diastole × 100), E/e' ratio, and left atrial volume index were determined. Nine GD1 patients also exhibited arterial hypertension. The intergroup difference of LV mass index and relative wall thickness was not significant. Transmitral E/A ratio was lower in HTN than in normal controls and GD1 (P < 0.05). GD1 exhibited longer DT than NC and HTN (P = 0.009). AFF was higher in GD1 and HTN compared to NC (P = 0.034). After adjustment for heart rate, GD1 was associated with longer DT (P < 0.001) and greater AFF (P = 0.036), while HTN was associated only with AFF (P = 0.013). No interaction was found between GD1 and HTN. In conclusion, GD1 is associated with subclinical LV diastolic dysfunction, which is independent of the coexistence of arterial hypertension. Subclinical LV impaired relaxation in the context of myocardial infiltrative damage could be the mechanism underlying these alterations.

Clinical characteristics and evolution of giant cell tumor occurring in Paget's disease of bone.

Patients with Paget's bone disease (PDB) have an increased risk of developing giant cell tumor (GCT). This study was performed to evaluate the clinical characteristics and evolution of GCT complicating PDB and to compare these clinical characteristics to those observed in two large PDB cohorts, the PDB Italian Registry and the United Kingdom's Multi-Centre Randomised Controlled Trial of Symptomatic Versus Intensive Bisphosphonate Therapy for Paget's Disease (PRISM) study. A systematic literature review identified 117 cases of PDB complicated by GCT (PDB-GCT), which involved the skeletal sites affected by PDB (110 patients) or the extraskeletal tissues adjacent to affected bones (7 patients). In contrast to what previously reported for GCT patients without GCT patients (83.2%) were white and one-fourth of them (24.8%) had multifocal GCTs. Compared to PDB patients without GCT, PDB-GCT patients showed a higher male/female ratio (2.1 versus 1.2) and more severe disease (age at PDB onset 52.1 ± 12.1 versus 63.3 ± 10.6 years; number of affected sites 6.1 ± 2.9 versus 2.34 ± 1.6; prevalence of polyostotic PDB 93.3% versus 60.6%). The mortality rate of PDB-GCT patients was higher than those occurring in GCT patients without PDB (about 50% versus 0% to 5% at 5 years) or in PDB patients without GCT (log rank = 29.002). Moreover, up to 98% of PDB-GCT cases had elevated total alkaline phosphatase levels at neoplasm diagnosis, suggestive of active PDB. Importantly, PDB-GCT patients from Southern Italy (45.6% of all GCT patients) showed a higher prevalence of multifocal GCT (51.7%) and of positive familial history for PDB (70.8%) and GCT (65.0%). Finally, indirect evidence suggests a decline in the incidence of GCT in PDB patients. The occurrence of GCT in PDB patients is associated with severe disease and reduced life expectancy of affected patients. The increased prevalence of familial diseases in PDB-GCT patients from Southern Italy suggests a founder effect. The observed changes over time in the incidence of GCT in PDB patients could be related to improved clinical management and/or living conditions of patients.

Vitamin D and cardiometabolic disorders.

Recent clinical and experimental studies suggest that vitamin D status could play a significant role in the pathogenesis of cardiometabolic disorders as well as in their clinical severity. In particular, low vitamin D levels appear to increase the risk of major cardiovascular events in apparently healthy individuals and to worsen the prognosis quoad vitam and quoad valetudinem following a cardiovascular event. The relevance of these observations is amplified by the high prevalence of vitamin D deficiency and insufficiency that affect over one billion individuals at all ages worldwide. Randomized controlled trials are currently underway in U.S., Europe and Oceania to demonstrate a cause-effect relationship by assessing the effects of vitamin D supplementation on various cardiovascular outcomes. Aim of this review is to point out the more recent advances in knowledge about the relationship between vitamin D status and the incidence, prevalence and pathogenesis of more common cardiometabolic disorders.

Nonsymmetric myocardial contribution to supranormal right ventricular function in the athlete's heart: combined assessment by speckle tracking and real time three-dimensional echocardiography.

PURPOSE: To investigate determinants of right ventricular (RV) function in competitive athletes by a combined assessment of speckle tracking (STE) and real time 3D echocardiography (RT3DE). METHODS: Right ventricular function of 40 top-level rowers was compared to 43 sedentary normal controls by standard Doppler echocardiography, RT3DE, and STE. RV diameters and wall thickness, tricuspid annular plane systolic excursion (TAPSE), tricuspid E/A ratio, and pulsed tissue Doppler of lateral tricuspid annulus were analyzed. RV volumes, ejection fraction (EF), and stroke volume (SV) were determined. RV global longitudinal strain (GLS) (average of 6 regions), septal strain (average of 3 septal regions, septal longitudinal strain [SLS]), and lateral strain (average of 3 lateral regions, lateral longitudinal strain [LLS]) were estimated by STE. RESULTS: The 2 groups were comparable for age, body mass index, and blood pressure, but heart rate was lower in rowers. RV diameters were larger and TAPSE, tricuspid E/A ratio, and tissue Doppler-derived s' and e' velocities were higher in rowers. By RT3DE, RV end-diastolic volume (EDV) and end-systolic volume were greater in rowers (both P < 0.0001), without difference in EF. GLS (P < 0.005) and LLS (P < 0.001), but not SLS, were greater in rowers. In pooled groups, LLS was related to EDV and SV, even after adjusting for heart rate, body mass index, and RV wall thickness by separate multiple linear regression analyses (ß coefficient = 0.247, P < 0.01 and ß = 0.225, P < 0.02, respectively). CONCLUSIONS: Right ventricular preload exerts its maximal influence on the longitudinal lateral fibers, which is independent on potential confounders and largely induces RV supranormal function in the athlete's heart.

The changing profile of patients with calcium nephrolithiasis and the ascendancy of overweight and obesity: a comparison of two patient series observed 25 years apart.

BACKGROUND: Epidemiological data indicate an increasing incidence and prevalence of nephrolithiasis (NL) worldwide in the last few decades. METHODS: The aim of this study was to compare the clinical and biochemical profiles of recurrent stone formers referred to a Kidney Stone Centre from March 1983 to June 1986 with the one featured by patients seen 25 years later in the same geographical area, Campania, southern Italy. RESULTS: Idiopathic calcium stone formers made up the large majority of the patient population in both series. Those examined in 2008-11 showed higher age at the onset of NL, higher prevalence of overweight/obesity and higher urinary excretion of oxalate and phosphate compared with those seen in 1983-86. The differences in the urinary biochemical variables remained significant upon accounting for age, gender, creatinine clearance and body mass index (BMI), and were not observed in patients with primary hyperparathyroidism enrolled in the same periods. A greater prevalence of uric acid stone formers was also observed in the 2008-11 population. CONCLUSIONS: The massive epidemics of overweight/obesity and the substantial modifications of dietary habits over the last few decades in most Western countries may be the factors underlying the changing clinical and biochemical profiles of patients with recurrent NL.

Resolution of angina pectoris and improvement of the coronary flow reserve after ranolazine treatment in a woman with isolated impaired coronary microcirculation.

In a 61-year-old woman with well controlled arterial hypertension, hypercholesterolemia, and smoke and suffering from recurrent angina pectoris despite angiographically normal epicardial coronary vessels and maximal therapy, the replacement of nitrates with novel antiangina drug ranolazine, after 6-month therapy, induced a complete relief of angina and a relevant rising of the transthoracic Doppler-derived coronary flow reserve (CFR). The present clinical case underlines therefore how in patients with chronic ischemic heart disease without epicardial coronary stenosis ranolazine can induce an improvement till the complete solution of the angina symptoms and a substantial increase of CFR as expression of the enhancement of the microvascular coronary function. The improvement of both symptoms and coronary microvascular function is strictly linked to the mechanism of action of the drug. Ranolazine induces in fact a reduction of the intracellular late sodium current that leads to a reduction of the intracellular calcium concentration thus producing a better myocardial diastolic relaxation process which in its turns enhances the myocardial perfusion. The ranolazine acts therefore as a lusitropic drug that improves the diastolic dysfunction and the segmental ischemia thus affecting one of the first steps of the ischemic cascade.

Giant cell tumor occurring in familial Paget's disease of bone: report of clinical characteristics and linkage analysis of a large pedigree.

Neoplastic degeneration represents a rare but serious complication of Paget's disease of bone (PDB). Although osteosarcomas have been described in up to 1% of PDB cases, giant cell tumors are less frequent and mainly occur in patients with polyostotic disease. We recently characterized a large pedigree with 14 affected members of whom four developed giant cell tumors at pagetic sites. The high number of affected subjects across multiple generations allowed us to better characterize the clinical phenotype and look for possible susceptibility loci. Of interest, all the affected members had polyostotic PDB, but subjects developing giant cell tumors showed an increased disease severity with a reduced clinical response to bisphosphonate treatment and an increased prevalence of bone pain, deformities, and fractures. Together with an increased occurrence of common pagetic complications, affected patients of this pedigree also evidenced a fivefold higher prevalence of coronary artery disease with respect to either the unaffected family members or a comparative cohort of 150 unrelated PDB cases from the same geographical area. This association was further enhanced in the four cases with PDB and giant cell tumors, all of them developing coronary artery disease before 60 years of age. Despite the early onset and the severe phenotype, PDB patients from this pedigree were negative for the presence of SQSTM1 or TNFRSF11A mutations, previously associated with enhanced disease severity. Genome-wide linkage analysis identified six possible candidate regions on chromosomes 1, 5, 6, 8, 10, and 20. Because the chromosome 8 and 10 loci were next to the TNFRSF11B and OPTN genes, we extended the genetic screening to these two genes, but we failed to identify any causative mutation at both the genomic and transcription level, suggesting that a different genetic defect is associated with PDB and potentially giant cell tumor of bone in this pedigree.

The melatonin receptor 1A (MTNR1A) gene is associated with recurrent and idiopathic calcium nephrolithiasis.

BACKGROUND: Experimental evidence indicate that melatonin regulates some renal tubular functions via specific melatonin receptors (MTNRs) located in the kidney of several avian and mammalian species, including humans. We hypothesized that single nucleotide polymorphisms (SNPs) in the melatonin receptor 1A gene (MTNR1A) might influence the risk of calcium nephrolithiasis. METHODS: We performed a systematic analysis of the MTNR1A gene in 246 recurrent calcium stone formers (136 men, 110 women; mean age 40.2 ± 12.0 years; body mass index 25.8 ± 4.5 kg/m2) and 269 healthy controls comparable for age and gender without a history of nephrolithiasis. RESULTS: Two SNPs in Intron 1 of MTNR1A were significantly associated with calcium nephrolithiasis: rs13140012 (P = 0.0004) and rs6553010 (P = 0.009). The haplotypes resulting from the two SNPs were also differently distributed between stone formers and controls, the haplotype A-T being more represented among stone formers (P = 0.00001) and the haplotype T-C being more common in healthy controls (P = 0.00001). Preliminary functional studies showed that the SNP rs13140012 could modify the binding sites for transcription factors. CONCLUSION: The results of this case-control study indicate a strong association between allelic variants of MTNR1A and recurrent calcium nephrolithiasis.

Characteristic clinical and biochemical profile of recurrent calcium-oxalate nephrolithiasis in patients with metabolic syndrome.

BACKGROUND: Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. METHODS: A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined on a free diet and after a sodium-restricted diet (sodium intake < 100 mmol/24 h). RESULTS: On free diet, stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176-218) vs 160 (150-168) mmol/24 h; P < 0.01] and lower citrate excretion [2.23 (1.99-2.58) vs 2.84 (2.51-3.17) mmol/24 h; P < 0.01] compared to controls, whereas stone formers without metabolic syndrome showed higher calcium and oxalate excretion [5.43 (5.01-5.82) vs 3.58 (2.84-4.19) and 0.34 (0.32-0.36) vs 0.26 (0.20-0.31)m mmol/24 h for calcium and oxalate, respectively; P < 0.01] and lower citrate excretion [2.18 (1.98-2.38) vs 2.84 (2.51-3.17) mmol/24 h; P < 0.01] compared to controls. The ion activity product of urinary calcium-oxalate salts was similar between stone formers with and without metabolic syndrome [1.41 (1.31-1.59) vs 1.40 (1.35-1.45); P > 0.05]. After the test diet, this index was lower in diet-compliant stone formers with metabolic syndrome compared to diet-compliant stone formers without metabolic syndrome [1.15 (1.10-1.21) vs 1.39 (1.31-1.45); P < 0.01]. CONCLUSIONS: The biochemical profiles and responses to the sodium-restricted diet were significantly different between stone formers with metabolic syndrome and those without. Dietary habits play a central role in the pathogenesis of nephrolithiasis in stone formers with metabolic syndrome.

Bone turnover and the osteoprotegerin-RANKL pathway in tumor-induced osteomalacia: a longitudinal study of five cases.

To evaluate serum levels of osteoprotegerin (OPG), soluble receptor activator of the nuclear factor-kappaB (RANKL), and their relationship with FGF-23, lumbar bone mineral density (BMD), and bone turnover markers, five patients with tumor-induced osteomalacia (TIO) and 40 healthy controls were studied. TIO patients were followed for 360 days after surgical removal of underlying tumor (n = 2) or beginning of therapy with phosphate and calcitriol when surgical treatment was impossible (n = 3). At diagnosis, TIO patients had higher levels of FGF-23 and bone-specific alkaline phosphatase (bALP) and lower levels of cathepsin K (CathK), RANKL, and RANKL/OPG ratio compared to controls. During the follow-up, FGF-23 decreased significantly only in patients who underwent a surgical excision, while phosphate and BMD increased in all patients. The increases in BMD, phosphate, and renal phosphate reabsorption rate were directly related. In the first 60 days of follow-up, we observed a prolonged inhibition of RANKL, CathK, and bone resorption markers associated with a persistence of TIO symptoms and an increase in bALP. From day 60, levels of bone turnover markers returned progressively within the normal range and a clinical remission was observed. The inhibition of the RANKL/OPG pathway and the uncoupling of bone formation and resorption observed in patients with active TIO may be a compensatory mechanism, attempting to reduce worsening of osteomalacia. The BMD increase during TIO treatment is related to the improvement of phosphate rather than FGF-23 levels. A "hungry bone"-like syndrome was observed after surgical or pharmacological treatment.