Importance of serum phosphate in elderly patients with diabetes mellitus

BACKGROUND

Metabolic disturbances including changes in serum calcium, magnesium or phosphate (P) influence the prevalence of type 2 diabetes mellitus (DM). We assessed the importance of serum P in elderly patients with type 2 DM vs non-diabetes mellitus (non-DM) in relation to renal function.

AIM

To determine the association between serum P and serum glucose or insulin resistance in diabetic and non-diabetic patients.

METHODS

One hundred-ten subjects with a mean age of 69.02 ± 14.3 years were enrolled. Twenty-nine of the participants had type 2 DM (26.4%). The incidence of hypertension, smoking and receiving vitamin D (vitD) derivates were recorded. The participants were classified by both estimated glomerular filtration rate (eGFR) and albuminuria categories according to the Kidney Disease Improving Global Outcomes 2012 criteria.

RESULTS

We divided the patients in two groups according to the P cut-off point related to DM value. A comparison between high and low P showed that body mass index 30.2 ± 6.3 vs 28.1 ± 4.6 (P = 0.04), mean glucose 63.6 vs 50.2 (P = 0.03), uric acid 6.7 ± 1.6 vs 6.09 ± 1.7 (P = 0.05), mean intact-parathyroid hormone 68.06 vs 47.4 (P = 0.001), systolic blood pressure 147.4 ± 16.7 vs 140.2 ± 16.1 (P = 0.02), mean albuminuria 63.2 vs 50.6 (P = 0.04) and eGFR 45.6 ± 22.1 vs 55.4 ± 21.5 (P = 0.02) were significantly different. χ² tests showed a significant association between high P and DM, hypertension, receiving vitD, smoking and eGFR stage (χ² = 6.3, P = 0.01, χ² = 3.9, P = 0.03, χ² = 6.9, P = 0.009, χ² = 7.04, P = 0.01 and χ² = 7.36, P = 0.04, respectively). The adjusted model showed that older age, female gender and increased body mass index were significant predictors of type 2 DM when entering the covariates.

CONCLUSION

High serum P contributes to vascular and metabolic disturbances in elderly patients with type 2 DM and renal impairment.

Triglycerides to High-Density Lipoprotein Cholesterol Ratio Predicts Chronic Renal Disease in Patients without Diabetes Mellitus (STELLA Study)

BACKGROUND

The triglycerides to high-density lipoprotein cholesterol (TG/HDL-C) ratio has been included in the potential indices for atherosclerosis in chronic kidney disease (CKD). In this study, we addressed the role of the TG/HDL-C ratio on CKD prediction defined by both classified estimated glomerular filtration rate (eGFR) and classified urinary albumin-to-creatinine ratio (UACR) in non-diabetic participants.

METHODS

One hundred and eighty-three subjects with a mean age 67.3 ± 15.6 years old were included. Our participants were classified in both eGFR and UACR categories according to the Kidney Disease Improving Global Outcomes 2012 criteria. Estimated pulse wave velocity (ePWV) was calculated using an equation from age and mean blood pressure. The TG/HDL-C ratio was calculated. X2 tests and adjusted models were applied using confounders.

RESULTS

The TG/HDL-C ratio was inversely associated with eGFR and positively with both UACR and ePWV. We divided our patients in two groups according to the found ROC curve of the TG/HDL-C ratio cut-off point, either with an eGFR of less or more than 60 mL/min/1.73 m². X² tests showed significant association between the high TG/HDL-C ratio and classified eGFR, and classified UACR and hypertension (x² = 24.5, p = 0.001, x² = 12.5, p = 0.002 and x² = 12.6, p = 0.001, respectively). The adjusted model showed the high TG/HDL-C ratio to be an independent predictor for both a low eGFR and UACR (OR = 1.5, 1.2-1.9 and OR = 1.22, 1.02-1.47, respectively) in combination with old age and hypertension.

CONCLUSION

The TG/HDL-C ratio was revealed to be a potential predictor for both a low eGFR and micro/macroalbuminuria in non-diabetic patients. The arterial stiffening was included in the main underlying pathophysiological mechanisms.

Factors related to peripheral arterial disease in patients undergoing hemodialysis: the potential role of monocyte chemoattractant protein-1

Peripheral arterial disease (PAD) is substantially prevalent among patients in the end stage of renal disease (ESRD). We considered factors related to peripheral arterial disease in patients undergoing hemodialysis including the important role of monocyte chemoattractant protein-1 (MCP-1) serum concentrations. We studied 150 patients in on-line-predilution hemodiafiltration. Dialysis sufficiency was defined by Kt/V for urea. PAD was defined using clinical criteria, ankle-brachial index and Doppler ultrasound in the lower limbs. MCP-1 serum concentrations were measured using enzyme-linked immunoabsorbed assay (ΕLISA). We performed chi-square tests and logistic regression analysis to investigate risk factors for the prevalence of PAD in these patients including MCP-1 serum concentrations. The patients with manifested PAD had elevated MCP-1, higher BP, higher arterial stiffness markers, higher markers of malnutrition, uncontrolled metabolic acidosis, bone disease and lower obtained dialysis adequacy than the patients without PAD. The association between PAD manifestation and high MCP-1 was found significant (x² = 9.6, p = 0.001). The built logistic regression analysis showed that the high MCP-1 increased the risk for PAD 3.2 (95% C.I 1.3-8.2) folds after adjustment for confounders. PAD was also significantly associated with non-administration of vitamin D agents during dialysis (x² = 3.5, p = 0.04).Malnutrition, low-grade inflammation mainly defined by high MCP-1 serum concentrations, metabolic acidosis and bone disease were included in significant predictors for peripheral arterial disease in patients undergoing hemodiafiltration. The obtained dialysis sufficiency and the therapy during dialysis sessions seem to play an additional role in the demonstration of peripheral vascular disease in these patients.

Oxidized Low-Density Lipoprotein Serum Concentrations and Cardiovascular Morbidity in End Stage of Renal Disease

INTRODUCTION

Oxidized low-density lipoprotein (ox-LDL) is considered a main biomarker of oxidative stress, a common characteristic in end stage renal disease. We examined the relationship between ox-LDL serum concentrations and cardiovascular disease in permanent hemodiafiltration therapy patients.

METHODS

Ox-LDL values were measured by ELISA and were corrected for LDL-cholesterol (LDL-C) in 96 participants and in 45 healthy control subjects. We performed chi-square tests and adjusted models for the role of ox-LDL on cardiovascular morbidity including coronary artery disease, left ventricular hypertrophy, systolic, diastolic dysfunction and peripheral arterial disease.

RESULTS

ox-LDL/LDL-C values were significantly higher in patients than in control group (p = 0.02), due to increased ox-LDL serum levels rather than to low LDL-C. The unadjusted relationship between high ox-LDL/LDL-C and low ejection fraction was found significant (x² = 9.04, p = 0.003), although the association with the other cardiovascular manifestations was found non-significant. In the adjusted model for the prediction of systolic cardiac dysfunction, high ox-LDL/LDL-C, old age and non-administration of vitamin D supplementation during dialysis session were found to be significant predictors after adjustment to the confounder. Moreover, the association between systolic cardiac dysfunction and non-administration of vitamin D derivatives during dialysis sessions was found significant (x² = 6.9, p = 0.008).

CONCLUSIONS

This study showed a significant association between high ox-LDL and systolic cardiac dysfunction in permanent hemodiafiltration therapy patients. This relationship seems to be influenced by aging and pharmaceutical therapy during dialysis sessions, including vitamin D derivatives.

Mortality and Low Serum Bicarbonate Level in Patients on Hemodiafiltration versus Peritoneal Dialysis

Mortality is substantially elevated in patients on chronic kidney disease in comparison to general population. In this study, we observed the mortality rate in relation to risk factors including low serum bicarbonate level, coronary artery disease (CAD), and dialysis modality in patients on dialysis during a median follow-up time of 60 months. We studied 96 dialysis patients, 62 males and 34 females, on mean age 62.1 ± 14.27 years old. The treatment modalities which were applied were predilution hemodiafiltration (HDF, n = 76), and peritoneal dialysis (PD, n = 20). We performed Kaplan-Meier curves and a Cox-regression analysis to investigate significant risk factors for mortality including hypertension, diabetes mellitus, smoking, bone disease defined by intact-parathormone, serum albumin, serum bicarbonate levels < or >22 mEq/L, dialysis modality, and the existence of CAD. Cox-regression analysis revealed a significant impact of serum bicarbonate levels <22 mEq/L on mortality in combination to dialysis modality and CAD. The prevalence of CAD on mortality was found significant (log-rank = 5.507, P = 0.02). Furthermore, the impact of dialysis modality on mortality was shown significant (log rank = 22.4, P = 0.001), noting that during the first 28-30 months from the treatment initiation, the survival was better for PD; but then, the mortality was significantly increased comparatively to HDF. Uncorrected metabolic acidosis and CAD were shown as independent significant predictors for mortality in patients on renal replacement therapy. PD may provide worse survival after 2-2.5 years of treatment initiation than HDF.

The Relationship of Residual Renal Function with Cardiovascular Morbidity in Hemodialysis Patients and the Potential Role of Monocyte Chemoattractant Protein-1

BACKGROUND

Residual renal function (RRF) provides several benefits to patients on dialysis. Monocyte chemoattractant protein-1 (MCP-1) plays an important role in atherosclerotic lesions. We considered the relationship between RRF and cardiovascular morbidity and the significant role of MCP-1 serum concentrations in hemodiafiltration (HDF) patients.

METHODS

We enrolled 76 patients on on-line HDF. RRF was defined by interdialytic urine output, and we studied the patients in two groups according to the preservation or not of urine output. MCP-1 levels were measured using enzyme-linked immunosorbent assay. χ2 tests were applied for the association between RRF and left ventricular hypertrophy (LVH), coronary artery disease (CAD), peripheral artery disease (PAD), and systolic and diastolic cardiac dysfunction. We built an adjusted model using logistic regression analysis for the factors which might impact on the loss of urine output.

RESULTS

χ2 tests showed a significant association between the loss of urine output and LVH, diastolic dysfunction, and PAD (χ2 = 7.4, p = 0.007; χ2 = 14.3, p = 0.001; χ2 = 4.2, p = 0.03, respectively), although the association with CAD and systolic dysfunction was found to be nonsignificant. The patients without RRF had significantly higher MCP-1, and the urine volume was inversely associated with MCP-1 (r = -465, p = 0.03). In the built adjusted model, the elevated MCP-1 was found to be a significant predictor for the loss of RRF.

CONCLUSION

The loss of RRF was significantly associated with LVH, diastolic dysfunction, and PAD in HDF patients. The increased MCP-1, affected by the lack of urine, may act as an additional underlying factor on this relationship, reflecting a progressive inflammation/oxidative stress condition.

The Association between Intradialytic Hypertension and Metabolic Disorders in End Stage Renal Disease

BACKGROUND

Intradialytic hypertension was associated with a high mortality risk. We examined the relationship between intradialytic hypertension and metabolic disorders in hemodialysis treatment patients.

METHODS

We studied 76 patients in online hemodiafiltration. Dialysis adequacy was defined by Kt/V for urea. Normalized protein catabolic rate (nPCR), as a marker of protein intake, was calculated. Sodium removal was determined as percent sodium removal. Metabolic acidosis was determined by serum bicarbonate less than 22 mmol/L. Interdialytic urine volume more than 100 ml was recorded. Intradialytic hypertension was defined by an increase in systolic blood pressure equal to 10 mmHg from pre- to posthemodialysis. Arterial stiffness was assessed as carotid-femoral pulse wave velocity (c-fPWV) and carotid augmentation index (AIx). Chi-square tests and logistic regression analysis were applied for intradialytic hypertension prediction.

RESULTS

Patients with intradialytic hypertension were older and had significantly lower hemoglobin, nPCR, urine output, and serum bicarbonate and significantly higher c-fPWV, though similar Kt/V for urea, than patients without intradialytic hypertension. They also had increased sodium removal and pulse pressure related to less urine output. Serum bicarbonate was inversely associated with c-fPWV (r = -0.377, p = 0.001). Chi-square test showed significant association between intradialytic hypertension and serum bicarbonate < 22 mmol/L (x² = 5.6, p = 0.01), which was supported by an adjusted model.

CONCLUSION

The intradialytic hypertension was significantly associated with metabolic disorders including malnutrition/inflammation and uncontrolled metabolic acidosis in hemodialysis treatment patients. Severe metabolic acidosis may reflect sodium imbalance and hemodynamic instability of these patients resulting in volume overload and increased vascular resistance.

Association between Low Serum Bicarbonate Concentrations and Cardiovascular Disease in Patients in the End-Stage of Renal Disease

BACKGROUND

Metabolic acidosis, a common condition particularly in the end-stage of renal disease patients, results in malnutrition, inflammation and oxidative stress. In this study, we focused on the association between low serum bicarbonate and cardiovascular disease in patients on intermittent dialysis.

METHODS

We studied 52 on-line-pre-dilution hemodiafiltration (on-l HDF) patients, 32 males and 20 females, with a mean age of 58.01 ± 15.4 years old. Metabolic acidosis was determined by serum bicarbonate concentrations less than 22 mmol/L. Residual renal function (RRF) was defined by interdialytic urine volume. Kaplan-Meier curves and Cox regression models were performed to predict coronary artery disease (CAD), defined by ejection fraction <50%, or diastolic dysfunction congestive heart failure (CHF) and peripheral vascular disease (PVD).

RESULTS

Kaplan-Meier analyses showed that a lower or higher than 22 mmol/L serum bicarbonate metabolic acidosis status was significantly associated with both PVD and diastolic dysfunction (log-rank = 5.07, p = 0.02 and log-rank = 5.84, p = 0.01, respectively). A similar prevalence of serum bicarbonate on CAD or CHF by low ejection fraction was not shown. The RRF was associated with PVD event and serum bicarbonate less than 22 mmol/L (log-rank = 5.49, p = 0.01 and log-rank = 3.9, p = 0.04, respectively). Cox regression analysis revealed that serum bicarbonate and RRF were significant risk factors for PVD after adjustment for confounders. Furthermore, RRF adjusted for covariates was shown to be a significant risk factor for diastolic dysfunction.

CONCLUSION

Low serum bicarbonate was associated with peripheral vascular disease and diastolic dysfunction in intermittent dialysis. The residual renal function may impact patients' outcomes through its relationship with metabolic acidosis status, particularly for peripheral vascular disease manifestation.

The relationship between concentrations of magnesium and oxidized low-density lipoprotein and Beta2-microglobulin in the serum of patients on the end-stage of renal disease

The end-stage of renal disease is associated with increased oxidative stress and oxidative modification of low-density lipoproteins (LDLs). Beta2 microglobulin (beta2M) is accumulated in the serum of dialysis patients. Magnesium (Mg) plays a protective role in the development of oxidative stress in healthy subjects. We studied the relationship between concentrations of magnesium and oxidized LDL (ox-LDL) and beta2M in the serum of patients on the end stage of renal disease. In 96 patients on on-line- predilution hemodiafiltration, beta2M and intact parathormone were measured by radioimmunoassays. High-sensitivity C-reactive protein (hsCRP) and ox-LDL were measured using ΕLISA. Serum bicarbonate levels were measured in the blood gas analyser gas machine. We performed logistic regression analysis models to investigate Mg as an important independent predictor of elevated ox-LDL and high beta2M serum concentrations, after adjustment to traditional and specific for dialysis patients' factors. We observed a positive correlation of Mg with ox-LDL (r = 0.383, P = 0.001), but the association of Mg with beta2M, hsCRP, and serum bicarbonate levels was significantly inverse (r = -0.252, P = 0.01, r = -0.292, P = 0.004, and r = -0.282, P = 0.04 respectively). The built logistic-regression analysis showed that Mg act as a significant independent factor for the elevated ox-LDL and beta2M serum concentrations adjusting to traditional and specific factors for these patients. We observed a positive relationship between magnesium and acidosis status- related ox-LDL concentrations, but the inverse association between magnesium and beta2M serum concentrations in hemodialysis patients.

Glucose Serum Concentrations and Cardiovascular Disease in Patients on the End Stage of Renal Disease without Diabetes Mellitus

Background/Aim: It is still controversial whether tighter glycemic control is associated with better clinical outcomes in patients with kidney failure. We examined the association between glucose serum concentrations and cardiovascular disease in patients on the end stage of renal disease without diabetes mellitus. Methods: We studied 76 patients on on-line hemodiafiltration. Cardiovascular disease was defined by the existence of coronary disease (CD). Arterial stiffness was measured as carotid-femoral pulse wave velocity (c-fPWV) and carotid augmentation index (AIx). The concentrations of beta2-microglobulin (β2M) and insulin were measured by radioimmunoassays and insulin resistance by HOMA-IR. We built a logistic-regression analysis to examine the role of glucose on cardiovascular disease after adjustment for the traditional and specific risk factors for dialysis patients. Results: Serum glucose was positively correlated with beta2M, insulin and HOMA-IR (r = 0.361, p = 0.002, r = 0.581, p = 0.001 and r = 0.753, p = 0.001 respectively). Logistic-regression analysis did not show significant impact of glucose concentrations on cardiovascular disease after adjustment for traditional and specific risk factors. Conclusions: The association between elevated glucose serum concentrations and represented by coronary syndrome cardiovascular disease in patients on the end stage of renal disease without diabetes mellitus was not found significant.

The relationship between glycemic control, beta2-microglobulin and inflammation in patients on maintenance dialysis treatment

BACKGROUND

Hyperglycemia appears to play a significant role on the inflammatory cytokines production. Beta2-microglobulin (beta2M) is accumulated in the circulation of dialysis patients. We studied the relationship between glycemic control defined by glucose serum concentrations and insulin resistance, beta2M and markers of inflammation in patients on renal replacement therapies with or/and without diabetes mellitus.

METHODS

We enrolled 96 dialyzed patients, 62 males and 34 females. The treatment modalities which were applied were : regular hemodialysis (HD, n = 34), predilution hemodiafiltration (HDF, n = 42) and peritoneal dialysis (PD, n = 20). Dialysis adequacy was defined by Kt/V for urea.Beta2M and insulin serum concentrations were measured by radioimmunoassays. hsCRP and TNF-α serum concentrations were measured by ELISA. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR).We examined the association of elevated serum glucose with inflammatory factors and we built a multivariable model to investigate if glucose could be a potential determinant of beta2M serum levels.

RESULTS

Serum glucose was positively correlated with beta2M and TNF-α (r = 0.320, p = 0.002 and r = 0.215, p = 0.03 respectively).We observed significant association between the patients with higher serum glucose concentrations and the patients with greater beta2Μ concentrations (x(2) = 4.44, p = 0.03). Multivariable model showed that glucose acts as a significant independent determinant of beta2M adjusting for age, gender, dialysis modality and metabolic acidosis status.

CONCLUSIONS

The elevated glucose concentrations were positively associated with both, greater beta2M serum concentrations and up-regulated inflammatory procedure in dialysis patients with or/and without diabetes mellitus.

β2-Microglobulin, pulse pressure and metabolic alterations in hemodialysis patients

BACKGROUND/AIM

Pulse pressure (PP) is a result of arterial stiffness seen in dialysis patients, but may be a consequence of fluid overload. We examined the role of β(2)-microglobulin (β(2)M) in PP in relation to metabolic alterations in patients on different hemodialysis (HD) modalities.

METHODS

We studied 76 hemodialyzed patients on regular HD (n = 34), predilution bagged hemodiafiltration (n = 19) and online predilution hemodiafiltration (n = 23). β(2)M levels were measured by radioimmunoassay, and the clearance of β(2)M was assessed by Kt/V for β(2)M. Arterial stiffness was measured as carotid-femoral pulse wave velocity, and PP was derived. Insulin levels were measured using immunoradioassay, and insulin resistance was calculated using homeostasis model assessment insulin resistance (HOMA-IR). Serum bicarbonate levels were measured using a blood gas analyzer, and percent sodium removal was calculated.

RESULTS

β(2)M levels predict increased PP (p = 0.02) adjusting for age, HD modalities, HD duration, HOMA-IR and percent sodium removal. β(2)M was positively associated with HOMA-IR (r = 0.306, p = 0.007). Serum bicarbonate levels and carotid-femoral pulse wave velocity were inversely associated (r = -0.719, p = 0.001).

CONCLUSIONS

β(2)M levels were positively associated with PP, which was influenced mainly by dialysis modality fluid and sodium balance and less by arterial stiffness. β(2)M levels were positively associated with insulin resistance. Uremic acidosis may contribute to arterial stiffness.

The association between the spatial QRS-T angle with cardiac autonomic neuropathy in subjects with Type 2 diabetes mellitus

AIMS

To examine differences in the spatial QRS-T angle in patients with Type 2 diabetes mellitus with and without cardiac autonomic neuropathy.

METHODS

Two hundred and thirty-two patients with diabetes mellitus (105 with cardiac autonomic neuropathy and 127 without cardiac autonomic neuropathy) and 232 control subjects, matched by gender and age, were studied. Diagnosis of cardiac autonomic neuropathy was based on the classic autonomic function tests. All subjects underwent a digital electrocardiographic recording. Electrocardiographic parameters were measured using the Modular Electrocardiographic Analysis (MEANS) program. Left ventricular mass index (LVMi) and global myocardial performance index (Tei index) of the left ventricle were assessed by ultrasonography.

RESULTS

The spatial QRS-T angle was higher in the patients with diabetes in comparison with the control subjects (24.5 ± 10.7 vs. 9.7 ± 4.5°, P < 0.001) and in the patients with diabetes and cardiac autonomic neuropathy than in those without cardiac autonomic neuropathy (30.1 ± 11.3 vs. 19.5 ± 7.1, P < 0.001). No differences were found in the QT interval between the studied groups. Multivariate linear regression analysis in subjects with diabetes after controlling for age, gender, BMI, blood pressure, diabetes duration, HbA(1c) , lipids, microalbuminuria and insulin resistance, demonstrated significant and independent associations between the spatial QRS-T angle with presence and severity of cardiac autonomic neuropathy, all parameters of heart rate variability, LVMi and Tei index.

CONCLUSIONS

The spatial QRS-T angle is increased in patients with Type 2 diabetes who have cardiac autonomic neuropathy, suggesting increased ventricular arrhythmogenicity, and is associated with the structural and functional properties of the myocardium. Further research is warranted to evaluate its role in cardiovascular risk stratification of patients with diabetes.

Circulating antibodies to endogenous erythropoietin and risk for HIV-1-related anemia

OBJECTIVES

In a previous retrospective study we have shown that circulating antibodies to endogenous erythropoietin (anti-EPO) are associated with HIV-1-related anemia. The present longitudinal cohort study was conducted to examine the effect of anti-EPO on the risk of developing anemia over time.

METHODS

The study population consisted of 113 HIV-1 seropositive patients, who were screened for the presence of anti-EPO, with a mean+/-SD follow up of 105+/-40 months, for a total of 2190 visits. Anti-EPO were detected with an ELISA assay.

RESULTS

Anti-EPO were detected in 41% (46/113) at enrollment and 29% (320/1094) for all visits, and were associated with higher EPO levels for all visits (45.7+/-60.4 vs. 31.8+/-31.7 IU/ml, p<0.001). After adjusting for other significant confounders, anti-EPO has been associated with increased risk of anemia both at enrollment (odds ratio [OR], 5.07; 95% confidence interval [CI], 1.25-20.49) as well as for all visits ([OR], 2.15; 95% [CI]: 1.29-3.56). During follow up, a decline in prevalence of both anti-EPO and anemia was observed as the percentage of patients receiving HAART was increasing.

CONCLUSIONS

Anti-EPO are an independent risk factor for anemia in HIV-1-infected patients. HAART seems to reduce both anti-EPO and anemia prevalence.

Increased plasma ghrelin levels in chronic renal failure are not associated with hemodynamic parameters

BACKGROUND/AIMS

Hardly anything is known about the effect of renal function on plasma ghrelin levels. Ghrelin is an orexigenic hormone with important hemodynamic effects. We examined differences in plasma ghrelin levels between chronic renal failure (CRF) patients and healthy subjects, and ghrelin's relationship with indices of left ventricular (LV) function.

METHODS

Fasting total plasma ghrelin levels were measured in 122 CRF patients (57 on, 65 not on hemodialysis) and 57 control subjects. Indices of LV function were evaluated using echocardiography.

RESULTS

Total plasma ghrelin levels were higher in patients with CRF compared to controls, but were not different between patients on and those not on hemodialysis. In a multivariate linear regression model, presence of kidney dysfunction explained 41 % of the variability of ghrelin values. The etiology of renal failure (diabetic nephropathy or not) had no influence on ghrelin levels in the renal patients. Ghrelin levels were not associated with indices of LV systolic function or blood pressure in these patients.

CONCLUSION

Fasting plasma ghrelin concentrations are higher in CRF patients regardless of their need for hemodialysis compared to controls. The etiology of renal failure does not have any effect on plasma ghrelin levels. In addition, ghrelin levels are not associated with hemodynamic parameters in patients with CRF.

Acute nateglinide administration in subjects with type 2 diabetes: effects on postprandial metabolism, coagulation, and fibrinolysis

BACKGROUND AND AIM

Postprandial glycaemia and lipaemia are known risk factors for atherosclerosis in type 2 diabetes. Coagulation activation in the postprandial state also contributes to acceleration of atherosclerosis. Nateglinide is effective in reducing postprandial glycaemia. Its effect on glycaemia may also be beneficial in postprandial lipaemia and coagulation. The aim of this study was to examine the potential effect of a single dose of nateglinide on postprandial triglyceridaemia, coagulation, and fibrinolysis in patients with type 2 diabetes.

METHODS AND RESULTS

Ten subjects with type 2 diabetes, treated with diet alone were recruited in a crossover randomized study. In the morning, after a 12- to 14-h fast, each subject received a standard mixed meal (total energy 783 kcal), preceded by one tablet of 120 mg nateglinide or placebo. Venous blood samples were drawn prior to meal consumption and 6h afterwards for the measurement of plasma glucose, insulin, and C-peptide, lipids, coagulation, and fibrinolysis factors. As expected, there was a significant reduction in postprandial glycaemia after nateglinide administration compared to placebo (P<0.001). Plasma insulin levels were significantly higher after nateglinide than after placebo (P=0.002). Nateglinide administration resulted in a lower overall postprandial reduction of tissue-plasminogen activator than placebo (-2.9+/-1.3 vs. -8.3+/-3.7 ng/ml h, P=0.003). In addition, a significant reduction of postprandial plasminogen activator inhibitor-1 was observed in comparison with the baseline values after nateglinide (P=0.001), although the overall response was not significantly different after nateglinide and placebo (P=0.31). Plasma concentrations of C-peptide, lipids and the remaining coagulation parameters studied were not different between nateglinide and placebo.

CONCLUSIONS

Acute nateglinide administration improves postprandial glycaemia and fibrinolytic activity in patients with type 2 diabetes. This combined effect, if confirmed by a long-treatment study, might reduce cardiovascular risk in type 2 diabetes.

Plasma adiponectin concentrations in patients with chronic renal failure: relationship with metabolic risk factors and ischemic heart disease

AIMS

To compare plasma adiponectin levels between healthy controls and patients with chronic renal failure and to examine for a relationship between plasma adiponectin levels and ischemic heart disease as well as aortic distensibility which is an early marker of atherosclerosis.

METHODS

We included 89 patients with CRF (45 on and 44 not on hemodialysis) and 70 controls in a cross-sectional study. Plasma adiponectin levels were measured by radioimmunoassay. Aortic distensibility was assessed by high-resolution ultrasonography.

RESULTS

Plasma adiponectin levels were significantly almost twice as high in patients with renal failure compared to controls (9.7 +/- 1.1 vs. 5.4 +/- 0.6 microg/ml, p < 0.0001). No significant differences were found between renal patients on hemodialysis and not on hemodialysis (p = 0.71). Multivariate linear regression analysis in the renal patient group demonstrated a significant negative relationship between plasma adiponectin levels and ischemic heart disease (p = 0.02). The same analysis in the control subjects group showed a significant, negative relationship between plasma adiponectin levels and body mass index (p = 0.02) and a highly significant positive relationship with the high density lipoprotein cholesterol (p < 0.0001). In the total study population, glomerular filtration rate was the only independent predictor of plasma adiponectin concentrations. Aortic distensibility was lower in renal patients than in controls at a high level of significance (p < 0.0001). However, no significant relationship could be found between plasma adiponectin and aortic distensibility in either the controls or the renal patients.

CONCLUSIONS

Plasma adiponectin levels are almost twice as high in patients with chronic renal failure in comparison with healthy controls, but not different between renal patients on and those not on hemodialysis. In addition, low plasma adiponectin levels are strongly associated with ischemic heart disease, but not with aortic distensibility in chronic renal failure.

Differential effects of high-fat and high-carbohydrate content isoenergetic meals on plasma active ghrelin concentrations in lean and obese women

AIM

To study the effect of two different isoenergetic meals, one rich in carbohydrates and one rich in fat, on plasma active ghrelin levels in lean or obese subjects.

METHODS

Eight obese and eight lean women, strictly matched for age, were fed two isoenergetic meals of different composition, one rich in fat and one rich in carbohydrates (CHO), on separate days. Plasma active ghrelin levels were measured just before and at 1, 2 and 3 hours after meal consumption.

RESULTS

Overall, plasma active ghrelin levels were significantly lower in the obese compared to the lean women (71.7 +/- 29.7 vs. 222.2 +/- 127.2 pmol/liter respectively, p < 0.0001). Furthermore, ghrelin levels decreased significantly by 30 % from baseline values in the lean subjects in the first hour after the CHO-rich meal (mean difference +/- SD): -66.2 +/- 49.0 pmol/liter (p = 0.03), returning to near-baseline levels by 2 hours, while no significant change was observed in the obese subjects. After the fat-rich meal, active ghrelin levels did not change significantly in either group (p > 0.05).

CONCLUSIONS

A fat-rich meal does not suppress plasma active ghrelin levels in either lean or obese women. Moreover, in obese, unlike lean women, a high carbohydrate meal also fails to suppress plasma ghrelin levels, which are already quite low. This suggests that ghrelin-induced satiety mechanisms may be compromised in these subjects.

Pre-operative Tc-99m-sestamibi scanning and intra-operative nuclear mapping: are they accurate in localizing parathyroid adenomas?

PURPOSE

Presentation of the results of Tc-99m-sestamibi imaging in the pre-operative localization of parathyroid adenomas and the intra-operative localization of those lesions using a gamma detector (prospective study).

PATIENTS & METHODS

Eighteen consecutive patients aged 27-75 years with primary hyperparathyroidism (PHPT) underwent Tc-99m-sestamibi scanning 1-2 hours before the operation and the presence of a single adenoma was recognized. All our patients underwent bilateral neck exploration based on pre-operative scanning and intra-operative gamma detector guidance and the adenoma was detected in the positions shown by both methods.

RESULTS

In 16 patients we found a single adenoma localized in the same position shown by pre-operative scanning, while the intra-operative method accurately revealed all abnormal glands. In one of the two patients where an inaccurate pre-operative localization technique had been carried out, we performed thyroid lobectomy (the adenoma proved to be intrathyroidal), while the other one had an adenoma which was not close to the site indicated by the pre-operative scintigraphy. Serum calcium reverted to normal within a few days postoperatively.

CONCLUSION

Patients with true-positive scans for single parathyroid adenoma could be eligible for minimally invasive operations since the abnormal gland is easily identified by the above-mentioned methods.

Differential effects of high-fat and high-carbohydrate isoenergetic meals on cardiac autonomic nervous system activity in lean and obese women

Food ingestion can influence autonomic nervous system activity. This study compares the effects of 2 different isoenergetic meals on sympathetic nervous system (SNS) activity, assessed by heart rate variability (HRV) and plasma norepinephrine (NE) levels, in lean and obese women. Fifteen lean and 15 obese healthy women were examined on 2 occasions: after a carbohydrate (CHO)-rich and after a fat-rich test meal. Measurements of blood pressure, heart rate, resting energy expenditure, plasma glucose, lipids, insulin, leptin, and NE, as well as spectral analysis of the HRV, were performed at baseline and every 1 hour for 3 hours after meals. At baseline, obese women had higher SNS activity than lean controls (higher values of low-to-high frequency ratio [LF/HF], 1.52 +/- 0.31 v 0.78 +/- 0.13, P=.04; and plasma NE levels, 405.6 +/- 197.9 v 240.5 +/- 95.8 pg/mL, P<.0001). After the CHO-rich meal a greater increase in LF/HF and in plasma NE levels was observed in lean, compared to obese women (1.21 +/- 0.6 v 0.32 +/- 0.06, P=.04; and 102.9 +/- 35.4 v 38.7 +/- 12.3 pg/mL, P=.01, respectively), while no differences were observed after the fat-rich meal. Meal-induced thermogenesis was higher after the CHO-rich as compared to the fat-rich meal and was comparable between lean and obese women. Changes in HRV were not associated with the thermogenic response to the test meals. In conclusion, consumption of a CHO-rich meal causes greater cardiac SNS activation in lean than in obese women, while fat ingestion does not result in any appreciable change in either group. SNS activation does not appear to influence the thermic effect of the food in either lean or obese women.

Paucity of Sjogren-like syndrome in a cohort of HIV-1-positive patients in the HAART era. Part II

OBJECTIVE

This study was performed in order to investigate the prevalence of Sjögren-like syndrome (SLS) in the highly active anti-retroviral therapy (HAART) era in a cohort of HIV-1-positive Greek patients.

METHODS

One hundred and thirty-one unselected patients were screened by the validated European Union (EU) criteria for Sjögren's syndrome. Of the 31 who gave a positive EU-validated questionnaire, 17 consented to undergo minor salivary gland biopsy and other tests.

RESULTS

Only two patients had a positive salivary gland biopsy and both belonged to the non-compliant HAART group, whereas none of the compliant HAART patients had histological findings.

CONCLUSIONS

It is concluded that SLS, the prevalence of which in the pre-HAART era was 7.8%, has disappeared, possibly as a result of the protective action of HAART.

Lack of Effect of Acute Repaglinide Administration on Postprandial Lipaemia in Patients with Type 2 Diabetes Mellitus

The effect of acute repaglinide administration (2 mg) on postprandial glycaemia and lipaemia has been examined in 20 subjects with type 2 diabetes mellitus. Each subject received in the morning, after a 12 to 14 h fast, a standard mixed meal (total energy 783 kcal), preceded by one tablet of 2 mg repaglinide or placebo. Chylomicrons and chylomicron-deficient plasma were prepared by ultracentrifugation. Triglyceride levels in CM fraction (CM-triglycerides) in total plasma as well as in CM-deficient plasma (non-CM-triglycerides) were determined. A significant reduction in postprandial glycaemia was observed after repaglinide administration compared to placebo ( p < 0.001). Plasma concentrations of total triglycerides, CM-triglycerides, non-CM-triglycerides, free fatty acids and the other plasma lipids measured, were not significantly different between the two phases of the study. It is concluded that, in contrast to sulphonylureas, acute repaglinide administration does not improve postprandial lipaemia in patients with type 2 diabetes.

Changes of plasma levels of gastrointestinal peptides over the course of acute pancreatitis. Any significance for the pathophysiology and treatment of acute pancreatitis?

BACKGROUND/AIMS

Acute pancreatitis may be accompanied by alterations of the secretion of pancreatic and gastrointestinal peptides as a result of pancreatic inflammation. These changes, that may constitute targets of therapeutic manipulation, led to the study of the serum levels of various pancreatic and gastrointestinal peptides over the course of acute pancreatitis before and after the administration of octreotide and ranitidine.

METHODOLOGY

Concentrations of gastrin, glucagon, vasoactive intestinal peptide, neurotensin and pancreatic polypeptide were determined by radioimmunoassay in the plasma of 22 patients with acute pancreatitis on the first, sixth and 11th day of the disease. All patients were treated with octreotide s.c. while 14 of them were also administered ranitidine i.v. Treatment was initiated after taking the first blood sample.

RESULTS

Mean gastrin levels in patients receiving ranitidine was 56.76 ng/L and in patients not receiving ranitidine 47.16 ng/L on the first day (pNS) remaining stable throughout the course of acute pancreatitis. Mean glucagon, vasoactive intestinal peptide, neurotensin and pancreatic polypeptide levels on the first day were 52.05 pmol/L, 8.90 pmol/L, 9.80 pmol/L and 22.06 pmol/L, respectively, and no changes were found through the course of acute pancreatitis.

CONCLUSIONS

Plasma levels of gastrointestinal peptides remain constant over time and they are not significantly affected by the administration of octreotide or ranitidine. However more studies are necessary to document the significance of these findings.

Anaemia in systemic lupus erythematosus: aetiological profile and the role of erythropoietin

OBJECTIVE

To study the prevalence of different causes of anaemia in patients with systemic lupus erythematosus (SLE) and their associations with immunological and clinical parameters and to evaluate the contribution of erythropoietin (Epo) and anti-erythropoietin (anti-Epo) autoantibodies to the development of SLE anaemia.

METHODS

132 SLE patients with anaemia (defined as haemoglobin of 12 g/dl or less for women and 13.5 g/dl or less for men) from among a total of 345 consecutive SLE patients were prospectively enrolled into the study. Standard haematological and immunological tests were performed and serum Epo and anti-Epo antibodies were assayed.

RESULTS

The identified causes were anaemia of chronic disease (ACD) n=49 (37.1%), iron deficiency anaemia (IDA) n = 47 (35.6%), autoimmune haemolytic anaemia (AHA) n = 19 (14.4%) and other causes n = 17 (12.9%). There was significant heterogeneity in the severity of anaemia between the four groups (p<0.01) with AHA cases being on average more severe. The proportion of patients with anticardiolipin antibodies, low complement levels and anti-dsDNA differed significantly among the four groups; these markers were particularly common in patients with AHA, and uncommon in patients with IDA. Twenty one of 100 tested patients had anti-Epo antibodies. Such antibodies were seen practically only in patients with ACD (odds ratio 3.1, p = 0.041) and in patients with high lupus activity (ECLAM) scores (odds ratio 1.27 per point, p = 0.055). Epo response was inadequate in 42.4% and 41.2% of patients with ACD and AHA, respectively.

CONCLUSIONS

Anaemia in SLE usually takes the form of ACD and IDA, however autoimmune haemolysis is not uncommon. SLE patients with different causes of anaemia differ in regard to several immunological parameters. Epo response is blunted in anaemic SLE patients, particularly those with ACD and AHA.

Circulating autoantibodies to erythropoietin are associated with human immunodeficiency virus type 1-related anemia

In a cohort of 204 unselected consecutive human immunodeficiency virus type 1 (HIV-1)-infected patients, the association of circulating autoantibodies to endogenous erythropoietin (EPO) with HIV-1-related anemia was studied. Circulating autoantibodies to EPO were present in 48 (23.5%) of the 204 patients studied. Circulating autoantibodies were an independent predictor of anemia (odds ratio [OR]=5.0; 95% confidence interval [CI], 2.5-9.9), as strong as other known causes of anemia. The association of anti-EPO antibodies with anemia became stronger when the analysis was limited to the group of patients without any medical condition causing anemia (OR=10.4; 95% CI, 3.2-33.9). Moreover, the effect on hemoglobin levels remained significant even after adjusting for other anemia parameters. Anti-EPO autoantibodies were associated with higher EPO levels (r=.25, P=.012) and with a more prominent EPO response to anemia. Our findings suggest that autoimmunity, among other factors, may contribute to the pathogenesis of HIV-1-related anemia.

Moxonidine effect on microalbuminuria, thrombomodulin, and plasminogen activator inhibitor-1 levels in patients with essential hypertension

Increased sympathetic activity seems to play an important role in the pathogenesis and development of complications of atherosclerotic origin in patients with essential hypertension (EH). The aim of this study was to evaluate the effect of a new antihypertensive agent, moxonidine (M), on microalbuminuria (urine albumin excretion, UAE), plasma thrombomodulin (TM), and tissue plasminogen activator inhibitor (PAI-1) in patients with mild to moderate EH associated with increased UAE. Fifty-eight patients (32 M, 26 F) with EH and microalbuminuria, with a mean age of 56.6 +/- 8.2 years and a body mass index (BMI) of 23.8 +/- 3.1 kg/m2 who responded to M therapy (0.3-0.4 mg/daily) were studied before and after their blood pressure control. The 24-hour urine albumin excretion (RIA method), as well as TM and PAI-1 plasma levels (ELISA method), were determined before and 6 months after the initiation of treatment under moxonidine therapy. At the end of the 6-month period, all patients remained normotensive. The 24-hour urine albumin excretion had decreased to 24.5 +/- 6.4 vs. 32.3 +/- 7.2 ug/min before therapy (P < 0.001). The plasma TM levels had decreased to 44.0 +/- 7 vs. 51.0 +/- 9 ng/mL before therapy (P < 0.01), and PAI-1 levels had also decreased to 11.5 +/- 4.5 vs. 15.8 +/- 8 IU/mL before therapy (P < 0.05). The results of our study suggest that in hypertensive patients with microalbuminuria, moxonidine, an imidazoline I1-receptor agonist, a new centrally acting antihypertensive agent, significantly reduces urine albumin excretion as well as thrombomodulin and PAI-1 levels. These preliminary findings demonstrate a favorable effect on renal function and endothelial homeostatic mechanisms (maintenance of haemostatic balance).

Preliminary observations in the fasting serum gastrin in patients with duodenal ulcer; further evidence of the "clearing" effect of omeprazole on H pylori?

Thirty patients with active duodenal ulcer who were Helicobacter pylori positive (HP+) by HLO test and by histology (Giemsa stain) were given omeprazole (OME) 20 mg/d for a two-week period. Estimation of fasting serum gastrin concentration (RIA) was performed before treatment and 24 hours after the last dosage of OME, and HP was searched for an antral biopsies at the end of the treatment as well. Mean fasting serum gastrin concentration increased significantly after treatment in all patients studied (p less than 0.05). However, the increase remained significant only in those patients who continued to be HP+ while no significant increase was observed in those who became HP-. The results could be considered as further evidence of the 'clearing' effect of Omeprazole on HP.