Significance of the ionized calcium measurement to assess calcium status in osteopenic/osteoporosis postmenopausal outpatients.

INTRODUCTION: Evaluation of calcium status is important in the osteoporotic risk assessment. Although guidelines indicate total calcium (tCa) as first-line measurement, directly measured ionized calcium (m-iCa), considered as the gold standard, is more and more often required. Aim of this study is to evaluate the agreement between m-iCa, tCa and iCa calculated from a formula based on total calcium and albumin (c-iCa) in osteopenic/osteoporotic postmenopausal outpatients. METHODS: A total of 140 postmenopausal outpatients, 41 osteopenic (OPN) and 99 osteoporotic (OP) were enrolled. Levels of tCa, m-iCa, c-iCa, total protein and albumin, vitamin D (25-OHD), parathyroid hormone 1-84 (PTH), bone alkaline phosphatase, osteocalcin and serum collagen type 1 cross-linked C-telopeptide (CTX) were also measured. RESULTS: There were no statistically significant differences between OPN and OP groups regarding values of tCa, m-iCa, and c-iCa, 25-OHD and PTH. However, OP women had lower levels of CTX (p < 0.05). A significant direct correlation between m-iCa and tCa (r = 0.60, p < 0.001) and c-iCa (r = 0.61, p < 0.001) was found. Women with isolated hyper-m-iCa had similar DEXA parameter levels respect to the other patients. However, one patient with confirmed primary hyperparathyroidism presented hyper-m-iCa versus normal tCa and c-iCa values. CONCLUSIONS: The use of tCa could be sufficient to characterize the calcium status in postmenopausal outpatients, but reflexive calcium testing strategy for m-iCa test is necessary to women presenting the low or high extremes of tCa levels, or in women with suspected PHPT.

Low magnesium is not a significant predictor of hard events in acute myocardial infarction.

BACKGROUND: Although magnesium (Mg) has recognized cardioprotective properties and hypomagnesemia is common in patients with acute myocardial infarction (AMI), data regarding the role of Mg as prognostic factor for adverse events are scarce, as well as there are conflicting results on the use of Mg as adjuvant therapy in AMI. AIM: To evaluate the role of Mg as predictor for hard events (HE, all cause death, and nonfatal myocardial infarction) in AMI patients. DESIGN AND PATIENTS: We studied 406 AMI patients (306 males, age: 67 ± 12 years, mean ± SD). Patient data were collected from the Institute electronic databank which saves demographic, clinical, instrumental, therapeutical and follow-up data of all patients admitted to our Coronary Unit. RESULTS: During a mean follow-up period of 21 ± 18 months, the combined endpoint accounted for 63 HE, 44 (11%) deaths (35 cardiac deaths), 19 (5%) nonfatal MI. The multiple regression model identified glycemia as the only independent determinant of Mg in AMI pts. (T value = - 2.8, standard coefficient = - 0.15, p < 0.01). The Kaplan-Meier survival estimates failed to show a significantly worst outcome in patients presenting low Mg (< 0.783 mmol/L, 25th percentile). Aging (> 67 years-50th percentile), and ejection fraction (< 40%) remained as prognostic factors for HE in the adjusted Cox multivariate proportional hazard model (HR = 2.8, 95% CI = 1.6-5, p < 0.001; HR = 3.2, 95% CI = 1.9-5.3 p < 0.001, respectively). CONCLUSION: The present findings do not support a significant role of low Mg as predictor for HE in AMI.

Gender differences for uric acid as predictor of hard events in patients referred for coronary angiography.

AIM: To assess gender differences in uric acid (UA) as predictor for hard events (HE, mortality and nonfatal myocardial infarction) in a large cohort of patients referred for coronary angiography. Design & patients: 3020 inpatients (2177 males, age: 68 ± 9 years, mean ± SD) were retrospectively studied, collecting data from the Institute electronic databank which included demographic, clinical, instrumental and follow-up data. RESULTS: Although the Kaplan-Meier survival estimates showed a significantly worst outcome in female patients, high UA did not remained a significant predictor for HE after adjustment. Moreover, UA correlated with antioxidant capacity in both sexes. CONCLUSION: Hyperuricemia was not an independent risk for HE, and being correlated with antioxidant capacity, its elevation appears more likely compensatory than causative for HE.

Maternal high-fat feeding leads to alterations of brain glucose metabolism in the offspring: positron emission tomography study in a porcine model.

AIMS/HYPOTHESIS: Maternal obesity negatively affects fetal development. Abnormalities in brain glucose metabolism are predictive of metabolic-cognitive disorders. METHODS: We studied the offspring (aged 0, 1, 6, 12 months) of minipigs fed a normal vs high-fat diet (HFD), by positron emission tomography (PET) to measure brain glucose metabolism, and ex vivo assessments of brain insulin receptors (IRß) and GLUT4. RESULTS: At birth, brain glucose metabolism and IRß were twice as high in the offspring of HFD-fed than control mothers. During infancy and youth, brain glucose uptake, GLUT4 and IRß increased in the offspring of control mothers and decreased in those of HFD-fed mothers, leading to a 40-85% difference (p < 0.05), and severe glycogen depletion, lasting until adulthood. CONCLUSIONS/INTERPRETATION: Maternal high-fat feeding leads to brain glucose overexposure during fetal development, followed by long-lasting depression in brain glucose metabolism in minipigs. These features may predispose the offspring to develop metabolic-neurodegenerative diseases.

Analysis of the 2010-2012 results of the multicenter external proficiency study for 25-hydroxyvitamin D.

BACKGROUND: Results collected from the 2010-2012 cycles of the 'Immunocheck' external quality assessment scheme for 25-hydroxyvitamin D, conducted by QualiMedLab CNR (Italy) and ProBioQual (France; 250 among Italian and French laboratories) are presented in this article. METHODS: Details of how QualiMedLab operates can be found in QualiMedLab website. RESULTS: Interlaboratory imprecision was 19 (2010), 15 (2011) and 13% (2012). The LIAISON(®) analyzer (DiaSorin, Italy) was the most utilized, followed by Roche (UK), ImmunoDiagnostic Systems methods (UK), ARCHITECT (Abbott, IL, USA), radioimmunoassay (DiaSorin) and others. The within-method variability between laboratories (percentage coefficient of variation) were 15, 12.7 versus 9.8% for LIAISON, 27.8, 16.5 versus 11.7% for Roche, 15, 12 versus 17% for ImmunoDiagnostic Systems and 17.4, 18.6 versus 17.5% for radioimmunoassay in the 2010, 2011 versus 2012 cycles, and 15 versus 8.9% for ARCHITECT in the 2011 versus 2012, respectively. CONCLUSION: Significant differences in specific samples and discrepancies between laboratories and methods still exist, making the actuation of appropriate external quality assessment schemes mandatory.

A biomarker of oxidative stress as a nontraditional risk factor in obese subjects.

BACKGROUND: Oxidative stress has been postulated as an additive factor linking obesity to cardiovascular disease. MATERIALS & METHODS: Derivatives of reactive oxygen species metabolites (d-ROMs) were measured in 136 obese (42 males, 94 females; mean age: 47 ± 12 years; BMI: 36 ± 5 kg/m(2)) and in 306 over- and normal-weight subjects (112 males, 194 females; age: 47 ± 12 years; BMI: 24 ± 3 kg/m(2)). RESULTS: d-ROMs levels were higher in obese than in over- and normal-weight subjects (395 ± 104 vs 362 ± 102 and 351 ± 84 arbitrary units (AU); p < 0.001), in women than males (390 ± 104 vs 327 ± 68 AU; p < 0.001), in subjects with than those without hypertension (390 ± 103 vs 360 ± 95 AU; p < 0.01) and in smokers than former and nonsmokers (380 ± 97 vs 358 ± 97 AU; p < 0.05). A positive correlation was found between d-ROMs and BMI (r = 0.25; p < 0.001) and age (r = 0.13; p < 0.01). Levels of d-ROM (>75th percentile: 420 AU) remained as an independent obesity predictor (odds ratio: 2.5; p < 0.001) in women. Continuous variables are reported as mean ± standard deviation. CONCLUSION: d-ROMs are a powerful obesity predictor, and could represent a reliable tool in obesity and cardiovascular risk evaluation, especially in women.