Implications of premature ovarian failure on bone turnover markers and bone mineral density.

INTRODUCTION: Premature ovarian failure (POF) is the cessation of ovarian function before the age of 40. The loss of ovarian function, whether premature or not, has an overwhelming impact on female skeletal health, leading to an increased risk of developing osteoporosis because of the lengthened time of exposure to reduced estrogen. The objective of this study was to compare the implications of premature ovarian failure on bone turnover markers and bone mineral density in patients under the age of 40. MATERIALS AND METHODS: Sixty-one patients with a diagnosis of POF were selected for this prospective study. Patients were divided into two groups according to age, patients < 30 years old (n = 30), and patients > or = 30 years old (n = 31). RESULTS: Between the two age sub-groups (< 30 and > or = 30 years old), there was a significant difference in menopause rating scale (MRS), lumbar spine t-score, N-telopeptides crosslinks (NTx), and serum bone specific alkaline phosphatase (bALP) between the two age groups (10.93 +/- 7.79 vs 17.38 +/- 8.62; -1.84 +/- 1.47 vs -1.06 +/- 0.93; 58.80 +/- 21.32 vs 41.1 +/- 11.37; 48.99 +/- 42.16 vs 23.76 +/- 10.08, respectively). CONCLUSION: It is apparent that bone mineral density (BMD) is commonly less in women with POF than normal healthy women. Therefore, measurement of BMD is warranted. At this time, it is not clear how often the tests should be carried out to evaluate BMD. Further prospective studies are required to establish guidelines. However, it seems reasonable to monitor women with POF yearly for the presence of any endocrine dysfunction and to assess BMD at periodic intervals.

Alkaline phosphatase: can it be considered as an indicator of liver fibrosis in non-alcoholic steatohepatitis with type 2 diabetes?

OBJECTIVE: While isolated hepatosteatosis is a benign disease, in minority of cases non-alcoholic steatohepatitis (NASH) may even lead to cirrhosis in long-term. In order to find the stage of the disease and determine the prognosis, a liver biopsy is indicated. In this study, we studied the relationship of liver histopathological findings with serum levels of hepatic enzymes. METHODS: We recruited 52 cases of NASH with Type 2 diabetes mellitus. Diagnosis of NASH was made based on biochemical tests, ultrasound images and liver biopsy. RESULTS: Steatosis was mild in 57.7%, moderate in 30.8%, and severe in 11.6% of patients. While no infiltration was found in 78.8% of cases, there was a grade-1 infiltration in 15.4% and a grade-2 infiltration in 5.8% of cases. Similarly, no fibrosis was found in 42.3% of patients, but there was a stage-1 fibrosis in 50%, and a stage-2 fibrosis in 7.7% of cases. In patients with severe steatosis, serum levels of AST were higher than mild or moderate stage steatosis. Accordingly, in patients with no inflammation, serum levels of ALT were higher than in patients with inflammation. However, in patients with fibrosis, triglycerides levels were significantly lower and ALP was significantly higher than in patients without fibrosis. The correlation analysis indicated a positive association between serum levels of ALP and C-peptide. CONCLUSION: In addition to conventional risk factors such as age, presence of diabetes, female sex; higher levels of ALP may be considered as a risk factor linked to hepatic fibrosis in patients with NASH and type 2 diabetes (Tab. 6, Ref. 8).

Comparison of the metabolic and antioxidant effects of diltiazem and vitamin E on streptozotocin-diabetic rats.

In this study, solitary and combined effects of vitamin E and the calcium-channel blocker diltiazem were investigated in streptozotocin (STZ)-induced diabetic rats. Thirty male Wistar albino rats, weighing approximately 200 g were used. Diabetes mellitus was induced by a single intravenous injection of STZ at a dose of 65 mg/kg body weight. Five experimental groups were established as STZ-diabetic, STZ-diabetic + vitamin E, STZ-diabetic + diltiazem and STZ-diabetic + vitamin E + diltiazem. Vitamin E was injected intraperitoneally three times a week at a dose of 500 mg/kg body weight. Diltiazem was given orally every day at a dose of 25 mg/kg body weight. At the end of the study (10 weeks) blood glucose levels of diabetic rats, which had received vitamin E and diltiazem, had significantly decreased when compared with untreated diabetic rats (P < 0.02). Similarly, HbA1c levels had significantly decreased in diabetic rats which had received vitamin E (P < 0.05), diltiazem (P < 0.01) and vitamin E + diltiazem (P < 0.02) when compared with untreated diabetic rats. Liver glutathione levels of diabetic rats, which had received vitamin E (P < 0.01) and vitamin E + diltiazem (P < 0.05) had significantly increased when compared with untreated diabetic rats. Liver lipid peroxide levels had significantly decreased in diabetic rats, which had received vitamin E (P < 0.001) and diltiazem (P < 0.01). With respect to their metabolic and antioxidant effects, vitamin E proved superior to diltiazem.

Oxidative protein damage parameters in plasma in chronic experimental diabetes in rats.

An increase in oxidative stress may contribute to the development of oxidative protein damage (OPD) in the streptozotocin-diabetic rat. To show the effect of hyperglycemia in promoting OPD, we determined protein carbonyl (PCO), nitrotyrosine (NT), total thiol (T-SH) and advanced oxidation protein product (AOPP) levels as markers of OPD, and lipid hydroperoxide (LHP) levels as a marker of lipid peroxidation in plasma of acute and chronic diabetic male Sprague-Dawley rats and their controls. The levels of the studied markers, except NT, were determined by colorimetric methods. NT levels were measured by ELISA. Plasma PCO and AOPP levels of chronic diabetic rats were increased significantly compared with those of both acute diabetic rats and the controls. Plasma NT levels of the three groups were not different. Plasma T-SH levels of acute diabetics were increased significantly compared with those of the controls while T-SH increase in the chronic diabetics was not significant. Plasma LHP levels were increased significantly in the chronic diabetic rats compared with those of the controls. The increase in plasma PCO, AOPP, LHP levels in chronic but not in acute diabetic rats may be indicating that persistence of hyperglycemia is involved in the evolution of OPD while plasma NT levels do not seem to reflect OPD in diabetes.

An increase in lipoprotein oxidation and endogenous lipid peroxides in serum of obese women.

Endogenous malondialdehyde and diene conjugate levels, the susceptibility of apolipoprotein B-containing lipoproteins to copper-induced lipid peroxidation, and antibody titer against oxidized low-density lipoproteins were increased, but serum antioxidant activity was unchanged in obese women. Serum cholesterol, low-density lipoproteincholesterol, and trigliceride levels were also elevated, but high-density lipoprotein-cholesterol levels remained unchanged in obese women. In vitro, oxidation of apolipoprotein B-containing lipoproteins and levels of antibody against oxidized low-density lipoprotein correlated with body mass index, serum total cholesterol, and low-density lipoproteincholesterol levels in obese women. These results indicate that obesity is associated with increases in endogenous lipid peroxides, oxidation of low-density lipoproteins, and lipids in serum.

Determination of oxidative protein and lipid damage in adult hypopituitary patients with GH deficiency.

The aim of this study is to determine oxidative protein and lipid damage in adult hypopituitary GH-deficient patients. Eighteen hypopituitary GH-deficient--otherwise healthy-adults on conventional replacement therapy other than GH (9 male, 9 female, age 41.8 +/- 16.4 yr) and 18 healthy subjects (6 male, 12 female, age 40.3 +/- 16.2 yr) participated in the study. Plasma products of oxidative protein damage [protein carbonyl (PCO) and nitrotyrozine (NT)], plasma oxidized LDL (oxLDL), plasma product of oxidative lipid damage [lipid hydroperoxide (LHP)] and antioxidant status of the plasma [total thiol (T-SH)] were measured. Body fat percentage, total and LDL-cholesterol concentrations were significantly higher in the hypopituitary group. Plasma PCO, NT, LHP and T-SH concentrations did not differ significantly between patients and controls. OxLDL concentration was significantly higher in the hypopituitary patients (62.4 +/- 17.8 vs 43.1 +/- 11.3 U/l, p = 0.001). In the patients, oxLDL correlated significantly with the duration of hypopituitarism (r = 0.6323, p = 0.01). In the controls, oxLDL correlated significantly with blood pressure, total and VLDL-cholesterol concentrations. Increased oxLDL concentration may indicate increased oxidative stress within the vascular compartment and may contribute to the proatherogenic state in GH-deficient hypopituitary patients independent from conventional risk factors.

Relation of oxidative protein damage and nitrotyrosine levels in the aging rat brain.

An increase in oxidative stress may contribute to the development of oxidative protein damage in the aging rat brain. In the present study, we investigated the relation between nitrotyrosine levels and other oxidative protein damage parameters such as protein carbonyl and protein thiol, as well as oxidative stress parameters such as total thiol, nonprotein thiol, and lipid hydroperoxides in the brain tissue of young, adult, and old Wistar rats. Brain nitrotyrosine levels of old rats were significantly decreased compared with those of young rats. Young and adult rats were not significantly different as far as these parameters were concerned, however, brain protein carbonyl and lipid hydroperoxide levels of old rats were significantly increased compared with those of young and adult rats. On the other hand, brain tissue total thiol, nonprotein thiol, and protein thiol levels of old rats were significantly decreased compared with those of young and adult rats. The strong correlation we found between protein carbonyl and lipid hydroperoxide levels indicates a striking relation between protein oxidation and lipid peroxidation in the aging brain tissue. The results of this study suggest that protein carbonyl formation is both a sensitive and a specific marker of brain aging. However, decreased nitrotyrosine levels in old rats, in contradiction to the expected, may be due to mechanisms other than oxidative protein damage in the aging rat brain.

Antibodies against oxidised low-density lipoprotein in hypopituitary patients with growth hormone deficiency.

Growth hormone-deficient hypopituitary patients on conventional replacement therapy have increased mortality and morbidity from atherosclerotic cardiovascular disease. Oxidation of low-density lipoprotein (LDL) is a key event in the development and progression of atherosclerosis. Antibodies against oxidatively modified LDL may reflect in vivo oxidation processes. The aim of this study is to determine the effect of growth hormone deficiency on oxidised-LDL antibody titres in panhypopituitary patients taking conventional replacement therapy. Twenty-one GH deficient, adult panhypopituitary patients and 17 age, sex and body mass index-matched healthy controls were studied. After an overnight fast, anthropometric parameters were measured and body composition was determined by a bioelectrical impedance analyser. Venous blood samples were obtained for the measurements of biochemical parameters. Antibodies to oxidised-LDL were analysed by an ELISA system in the patients' and controls' serum. No significant difference was observed between the oxidised-LDL antibody titres in hypopituitary patients and controls (395.4+/- 183.2 mU/ml and 393.2 +/- 186.2 mU/ml respectively, p = NS). A significant positive correlation was observed between oxidised-LDL antibody titres and total cholesterol concentrations in the patients (r = 0.449, p < 0.05). No significant correlation was observed between oxidised-LDL antibody titres and anthropometric/biochemical variables in the controls. It is concluded that relatively increased LDL oxidation may not contribute to the progression of atherosclerosis in hypopituitary patients.

Oxidative protein damage in early stage Type 1 diabetic patients.

To examine the influence of oxidative stress on oxidative protein damage, we studied 51 young Type 1 diabetic patients clinically free of complications and 48 healthy normolipidaemic age-matched controls. We determined: (1) plasma carbonyl (PCO), plasma total thiol (T-SH), and nitrotyrosine (NT) levels as markers of oxidative protein damage; (2) plasma lipid hydroperoxide (LHP), and nitric oxide (NO) levels as markers of oxidative stress; (3) plasma total antioxidant capacity (TAO), ceruloplasmin (Cp), transferrin (TRF), unsaturated iron binding capacity (UIBC), erythrocyte glutathione (GSH), and erythrocyte superoxide dismutase (SOD) as markers of free radical scavengers. There were no significant differences in the levels of these markers between prepubertal diabetic patients and the controls. The levels of both of PCO and LHP were increased in adolescent and young adult Type 1 diabetic patients with respect to their controls. In the adolescent group, patient versus control values for PCO were 1.04+/-0.067 versus 0.67+/-0.0274 nmol/mg and for LHP they were 2. 10+/-1.09 versus 1.00+/-0.4 nmol/mg. In the young adult group, patient versus control values for PCO were 0.99+/-0.054 versus 0. 66+/-0.02 nmol/mg and for LHP they were 1.96+/-0.78 versus 1.15+/-0. 4 nmol/mg. TAO levels were significantly decreased in adolescent diabetic patients compared to their controls (0.92+/-0.27 vs. 1. 86+/-0.37) and in young adult diabetic patients compared to their controls (0.80+/-0.27 vs. 2.11+/-0.54 nmol/mg). T-SH was not different between diabetic patients and the controls. Serum NT, NO, and erythrocyte SOD levels were not different either between three groups of diabetic patients or between the patients and their controls. We attribute this lack of difference to limited disease duration. Changes in markers of oxidative stress other than NT, NO, and SOD observed in adolescent and young adult early stage Type 1 diabetic patients contribute to the imbalance in the redox status of the plasma. We attribute this imbalance to metal-catalyzed protein oxidation in both groups of Type 1 diabetic patients clinically free from complications.

Oxidative protein damage in type I diabetic patients with and without complications.

To examine the influence of oxidative stress on oxidative protein damage, we studied 47 Type I diabetic patients with and without complications. We determined plasma protein carbonyl, plasma protein thiol and nitrotyrosine levels as markers of oxidative protein damage, plasma lipid hydroperoxide levels as markers of oxidative stress, and plasma total thiol, plasma nonprotein thiol, erythrocyte glutathione, plasma ceruloplasmin, transferrin and total iron binding capacity as markers of free radical scavenging. There were no significant differences in nitrotyrosine, total plasma thiol, protein thiol, and erythrocyte glutathione levels between diabetic patients with complications and without complications. However, plasma protein carbonyl, lipid hydroperoxide, and nonprotein thiol levels were significantly increased in diabetic patients with complications compared with diabetic patients without complications. Although redox status of plasma is impaired in diabetic patients, we suppose these significantly different markers reflect enhanced oxidative protein damage in diabetic patients with complications.

The relation between salivary IgA and caries in renal transplant patients.

OBJECTIVE: The purpose of this study was to evaluate the effect of immunosuppressive drugs on the level of salivary immunoglobulin A (IgA) in patients who have received kidney transplants and the relation between the levels of salivary IgA and dental caries incidence. STUDY DESIGN: Patients who had undergone renal transplantation (n = 28, aged 18-54) were divided into 3 groups according to postsurgical period (0-6 months [G(1)], 6-12 months [G(2)], and >12 months [G(3)]). A healthy control group (n = 10, aged 17-49) was also included in this study. Saliva samples were collected from all patients by the spitting method. After collection, the samples were frozen immediately at -40 degrees C until analysis by the single radial immunodiffusion method. All fissure caries were examined clinically, and proximal caries were examined clinically and radiographically; caries status was determined according to the decay surface index. The findings were evaluated statistically by means of correlation analysis, the Kolmogorov-Smirnov test, and the 1-way Kruskal Wallis analysis of variance method. RESULTS: Salivary IgA levels of the patients who had undergone renal transplantation were found to be significantly lower than those of the control patients (G(1) = 6.76 mg/dL, G(2) = 6.80 mg/dL, G(3) = 7.84 mg/dL, and control group = 10.84 mg/dL, P <.001). However, the caries status of the patients who had undergone renal transplantation was not different from that of the control subjects for the first year after the transplant operation. The salivary IgA values of the 3 groups of patients who had undergone transplantation were not significantly different from each other. Thus, it was observed that a decrease in the level of salivary IgA does not result in an increase in caries incidence within 12 months after renal transplantation. The caries rate in the third group of patients who had undergone renal transplantation was found to be significantly different from those in the first and second groups. CONCLUSION: Low salivary IgA levels caused by immunosuppression are not correlated or associated with higher levels of dental caries within the first 12 months after renal transplantation. However, the incidence of dental caries was higher for patients who had undergone renal transplantation than for control subjects 12 months after renal transplantation. Because of the diagnostic processes used, dental caries may not become evident until after 12 months.

Changes in bone turnover and deoxypyridinoline levels in epileptic patients.

In this study, we evaluated bone turnover in 52 epileptic patients receiving chronic anticonvulsant therapy and in 39 healthy volunteers whose ages matched those of the patients. We determined serum osteocalcin and total and bone alkaline phosphatase levels as markers of bone formation, and urinary deoxypyridinoline and urinary calcium levels as markers of bone resorption. Statistical comparison of the levels of these markers between sexes in epileptic patients and their control groups revealed that total alkaline phosphatase levels were significantly increased in patients from both sexes compared with those of their controls. Urinary deoxypyridinoline levels of male epileptic patients were significantly increased compared with those of their controls. On the other hand, 25-hydroxyvitamin D levels of the male patients were significantly reduced compared with those of their controls. Serum osteocalcin, bone alkaline phosphatase, and urinary calcium levels of epileptic patients were not statistically different from those of the controls. We found that urinary deoxypyridinoline levels of male epileptic patients were increased, however, we observed no difference in serum osteocalcin and bone alkaline phosphatase levels. The lack of difference may be attributed to the fact that only the resorption phase of bone turnover is affected during chronic anticonvulsant therapy.

Effect of alpha-lipoic acid supplementation on oxidative protein damage in the streptozotocin-diabetic rat.

An increase in oxidative stress may contribute to the development of oxidative protein damage in streptozotocin diabetic rats. In the present study, the influence of alpha-lipoic acid supplementation on plasma protein carbonyl, plasma thiol, and plasma lipid hydroperoxide levels was examined in order to characterize the relationship between the oxidative stress and the oxidative protein damage. Rats were randomly divided into three groups of equal body weight. Chronic hyperglycemia was induced by intravenous streptozotocin injection in both the group of male Wistar rats to be supplemented with alpha-lipoic acid and the group that was not to receive alpha-lipoic acid. Nondiabetic rats formed the control group and received a saline injection. In streptozotocin diabetic rats with and without alpha-lipoic acid supplementation, plasma carbonyl levels were significantly increased, while plasma thiol levels were significantly decreased compared with those of the control group. Plasma lipid hydroperoxide levels were significantly increased in diabetic rats without alpha-lipoic acid supplementation compared with those of the controls, but the lipid hydroperoxide levels in the alpha-lipoic acid supplemented group were no different from those of the controls. In streptozotocin-diabetic rats, oxidative stress was significantly decreased in the alpha-lipoic acid-supplemented group. The results of this study suggest that alpha-lipoic acid, by decreasing oxidative stress, may be effective in preventing oxidative protein damage, which may contribute to the development of diabetic complications.

Oxidative protein damage in plasma of type 2 diabetic patients.

In this study, we evaluated protein oxidation in 84 patients with Type 2 diabetes with no complications and in 61 healthy volunteers who formed the control group, whose ages matched those of the patients. We determined plasma carbonyl and plasma thiol levels as markers of oxidative protein damage and erythrocyte glutathione, plasma ceruloplasmin and transferrin as markers of free radical scavengers. The concentrations (mean +/- SD) of both of plasma carbonyl (1.24 +/- 0.46 vs. 0.72 +/- 0.17 nmole/mg protein; p < 0.0001) and lipid hydroperoxides (1.8 +/- 0.63 vs. 1.3 +/- 0.21 micromole/l; p < 0.0001) were increased, and the concentration of plasma transferrin (3.85 +/- 0.65 vs. 4.59 +/- 0.79 g/l; p < 0.05) was decreased, respectively, in Type 2 diabetic patients compared with those of the controls. There were no significant differences in the concentrations of plasma thiol (0.0064 +/- 0.001 vs. 0.0068 +/- 0.001 micromole/mg protein), erythrocyte glutathione (2.54 +/- 0.57 vs. 2.65 +/- 0.56 mg/g Hb), plasma ceruloplasmin (548 +/- 107.30 vs. 609 +/- 93.34 mg/l) between the patients and the controls. These changes observed in diabetic patients contribute to the imbalance in the redox status of the plasma. We attribute this imbalance to oxidative protein damage in Type 2 diabetic patients clinically free of complications.

Changes in bone turnover on deoxypyridinoline levels in diabetic patients.

In this study, we evaluated bone turnover in 35 patients with non- insulin-dependent diabetes mellitus with no complications and in 35 healthy volunteers who formed the control group and whose ages matched those of the patients. We determined serum osteocalcin (OC) and total alkaline phosphatase levels as markers of bone formation, and urinary deoxypyridinoline (DPD) and urinary calcium levels as markers of bone resorption. Statistical comparison of the levels of these markers between sexes in diabetic and control groups revealed that the OC levels were significantly decreased in males and females in the diabetic group compared with those of the control group. No significant difference was observed for other markers. It was found that the OC levels of diabetic subjects were not affected by the type of therapy. No statistically significant difference was found in serum calcium, phosphorus and magnesium levels between the diabetic and the control groups. In our study, the finding that, in spite of the decrease in the OC levels in the diabetic group no difference was observed in DPD levels, was attributed to the fact that only the formation phase was affected in diabetes, while the resorption phase remained unaltered.

Serum lipids and apolipoprotein concentrations and plasma fibronectin concentrations in renal transplant patients.

In those cases where hypertriglyceridaemia was present before renal transplantation, it persisted after transplantation, and hypercholesterolaemia also developed. We studied serum lipid, lipoprotein, and apolipoprotein concentrations and plasma fibronectin concentrations in 57 renal transplantation patients and 29 healthy controls. We concluded that atherosclerosis in renal transplantation patients might be related to alterations in the constitutions of lipoproteins and apolipoproteins, but fibronectin synthesized by vascular endothelial cells seemed not to be associated with the atherosclerotic process.

Serum insulin and blood glucose levels in breast-fed and formula-fed infants in the first week of life.

Serum insulin and blood glucose levels were measured in newborns aged four to eight hours and those aged seven days who were either breast fed or formula fed. With both types of feeding, the maximum serum insulin levels occurred 60 minutes postprandially in four- to eight-hour-old infants and 30 minutes postprandially in seven-day-old babies. Between breast-fed and formula-fed groups, no statistically significant difference was found in postprandial serum insulin levels or (except for the 90-minute values on the seventh day) in blood glucose levels. It may be necessary to examine the metabolic-endocrine responses to formula administered as the only feeding over a long period to determine whether formula feeding alters such physiologic mechanisms as pancreatic function and immunity in early life and thereby affects the development of the child.