HDL-Associated Paraoxonase 1 as a Bridge between Postmenopausal Osteoporosis and Cardiovascular Disease / 전남의대학술지

The association of postmenopausal osteoporosis (PMOP) with both atherosclerosis and vascular/valvular calcification is well known. Recently, ample evidence has suggested a common etiologic factor, namely, reduced HDL-associated paraoxonase 1 (PON1) activity, as a causative factor in the development of PMOP and cardiovascular disease (CVD). This common etiologic factor not only contributes to atherosclerotic diseases but also to PMOP following an almost identical mechanism including dysfunctional HDL and lipid oxidation. According to recent studies, lipid oxidation might improve osteoblastic transformation of vascular cells and obstruct such transformation in bone cells. The primary objective of this current review was to summarize the evidence revealing the role of HDL-associated PON1 enzyme in PMOP. Additionally, the review aimed to address some of the subjects that need further investigation in order to define whether hyperhomocysteinemia and sensitivity to lipid oxidation may be risk factors for PMOP.

HDL-Associated Paraoxonase 1 as a Bridge between Postmenopausal Osteoporosis and Cardiovascular Disease / 전남의대학술지

The association of postmenopausal osteoporosis (PMOP) with both atherosclerosis and vascular/valvular calcification is well known. Recently, ample evidence has suggested a common etiologic factor, namely, reduced HDL-associated paraoxonase 1 (PON1) activity, as a causative factor in the development of PMOP and cardiovascular disease (CVD). This common etiologic factor not only contributes to atherosclerotic diseases but also to PMOP following an almost identical mechanism including dysfunctional HDL and lipid oxidation. According to recent studies, lipid oxidation might improve osteoblastic transformation of vascular cells and obstruct such transformation in bone cells. The primary objective of this current review was to summarize the evidence revealing the role of HDL-associated PON1 enzyme in PMOP. Additionally, the review aimed to address some of the subjects that need further investigation in order to define whether hyperhomocysteinemia and sensitivity to lipid oxidation may be risk factors for PMOP.

Ischemia-Modified Albumin: Could It Be a New Oxidative Stress Biomarker for Colorectal Carcinoma?

BACKGROUND/AIMS: An impaired oxidative/antioxidative status plays an important role in the pathogenesis of many diseases, including cancer. The aim of this study was to evaluate the levels of the novel marker ischemia-modified albumin (IMA) and albumin-adjusted IMA (Adj-IMA) in patients with colorectal cancer (CRC) and look for the associations of these with the total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI). METHODS: Forty patients with CRC (19 females and 21 males; mean age, 56.5+/-2.1 years) and 39 age- and sex-matched healthy people (22 females and 17 males; mean age, 56.0+/-1.7 years) were included in this study. Serum levels of IMA, TAS, and TOS were analyzed, and the OSI was calculated. RESULTS: Serum IMA, TOS, and OSI levels were significantly higher in patients with CRC than in controls (p<0.0001), whereas TAS levels were significantly lower in CRC patients (p=0.03). There was no significant difference in serum Adj-IMA levels between groups (p=0.32). CONCLUSIONS: In this study, the oxidative/antioxidant status was impaired in favor of oxidative stress in CRC patients. This observation was not confirmed by IMA measurement. Further studies are needed to establish the relationship between IMA and oxidative stress parameters in CRC and other cancers.

Relationship between renal stone formation, mitral annular calcification and bone resorption markers

Mitral annular calcification [MAC] is associated with osteoporosis and there is evidence of reduced bone mineral density [BMD] in patients with renal stone formation [RSF]. Therefore, we designed this study to test if RSF was associated with MAC and if this association could be linked to bone resorption. Fifty-nine patients [mean age, 41.5 years] with RSF and 40 healthy subjects [mean age, 44.2 years] underwent screening for MAC and BMD, and measuurements were taken of serum and urine electrolytes, parathyroid hormone, alkaline phosphatase and urine dypyridoline. MAC was diagnosed in 11 [18%] patients with RSF compared with 1 [2.5%] control [P=.01]. Urine phosphorus, magnesium, sodium, potassium and chloride levels were lower [P<.001, P=.02, P<.001, P<.001 and P<.001, respectively], but serum alkaline phosphatase, calcium and potassium levels were higher [P=.008, P=.007 and P=.001, respectively] in patients with RSF versus those without RSF. None of these abnormalities were found in patients or subjects with MAC. Urine pyridoline levels were higher and T-scores were more negative [more osteopenic] in patients and subjects with MAC than in those without MAC [P=.01 and P=.004, respectively]. In a multivariate analysis, only T-scores and urine dipyridoline level were predictive of MAC [P=.03 and P=.04, respectively]. Screening for MAC and bone resorption markers in patients with RSF demonstrated a high incidence of MAC in these patients. The presence of MAC in patients with RSF was associated with bone resorption markers. This seemingly complex interrelationship between RSF, MAC and bone loss needs to be clarified in further studies

Increased levels of nitric oxide, cortisol and adrenomedullin in patients with chronic schizophrenia

To investigate the levels of serum cortisol, dehydroepiandrosterone sulfate [DHEA-S], nitric oxide [NO] and adrenomedullin [AM] in schizophrenic patients. Sixty-six male patients with chronic schizophrenia and 28 normal male subjects participated in this study. The duration of disease was 145 +/- 120 [mean +/- SD] months. Serum levels of cortisol and DHEA-S were measured by electrochemiluminescence; plasma nitrite levels as an index of NO were measured with the Griess reaction, while plasma AM concentration was measured by using high-performance liquid chromatography. Patients [12.48 +/- 3.2 micro g/dl], as compared to controls [10.31 +/- 3.1 micro g/dl], had higher levels of baseline cortisol [p < 0.05]. DHEA-S levels were lower in patients though this did not reach statistical significance [302 +/- 156 micro g/dl compared to control, 322 +/- 96 micro g/dl, p > 0.05]. The mean levels of plasma AM and NO in the schizophrenic group [44.33 +/- 5.07 pmol/l and 36.27 +/- 17.6 micro mol/l] were significantly higher than the levels in the control group [14.56 +/- 4.03 pmol/l and 32.54 +/- 7.14 micro mol/l; p < 0.001, p < 0.03, respectively]. There was a positive association between duration of disease and cortisol/DHEA-S ratio and cortisol level. The data show that schizophrenia is associated with abnormal levels of cortisol, DHEA-S, NO and AM