Bone damage in type 2 diabetes mellitus.

This review focuses on the mechanisms determining bone fragility in patients with type 2 diabetes mellitus (T2DM). Despite bone mineral density (BMD) is usually normal or more often increased in these patients, fracture incidence is high, probably because of altered bone "quality". The latter seems to depend on several, only partly elucidated, mechanisms, such as the increased skeletal content of advanced glycation end-products causing collagen deterioration, the altered differentiation of bone osteogenic cells, the altered bone turnover and micro-architecture. Disease duration, its severity and metabolic control, the type of therapy, the presence or absence of complications, as like as the other known predictors for falls, are all relevant contributing factors affecting fracture risk in T2DM. In these patients the estimate of fracture risk in the everyday clinical practice may be challenging, due to the lower predictive capacity of both BMD and risk factors-based algorithms (e.g. FRAX).

Approach in glucocorticoid-induced osteoporosis prevention: results from the Italian multicenter observational EGEO study.

Glucocorticoid-induced osteoporosis (GIO) is the most frequent cause of secondary osteoporosis. GIO is linked to glucocorticoids (GC) daily assumption with maximum effect within first months of treatment and decreasing to basal levels as the therapy is discontinued. In Italy, primary prevention of GIO is suggested when GC therapy (prednisone >5 mg/day or equivalent) is taken for longer than 3 months. Lazio GISMO (Italian Group for Study and Diagnosis of Bone Metabolism Diseases) group organized the GC and Osteoporosis Epidemiology study (EGEO) to evaluate physician's approach in preventing GIO. The study involved 19 osteoporosis centers. Patients taking long-term GC therapy were recruited and information collected: medical history and anthropometric data, GC therapy, primary disease, physician's specialty, osteopororosis screening, and pharmacological intervention. The study included 1334 patients. Mean age was 63 ± 13 yr; 243 (18%) patients had a history of falls from standing position in the previous 12 months, 78 (35%) vertebral fractures, 91 (41%) fractures other than vertebral, 27 (12%) femoral fractures, and 27 (12%) multiple sites fractures. The molecules of GC more often prescribed were prednisone and 6-metil prednisolone. One thousand and forty patients (78%) were taking GC for more than 6 months. GC therapy was prescribed more frequently by rheumatologists (62%). Antiosteoporotic drugs for GIO prevention were prescribed in 431 patients (32%). Among the patients, only 27% (360) received calcium and vitamin D supplements, and 39% (319) treated by rheumatologists received anti-resorptive drugs. In conclusion, our data show that in Italy, as already described elsewhere, only a small subpopulation of GC-treated patients was supported by an anti-osteoporotic therapy, indicating the need to further stimulate awareness of both patients and specialists, prescribing GC therapy, to an appropriate and prompt GIO prevention.

Chronic constipation in hypercalcemic patients with primary hyperparathyroidism.

BACKGROUND: Chronic constipation (C), among gastrointestinal symptoms, is commonly associated with primary hyperparathyroidism (PHPT) and probably attributable to hypercalcemia. OBJECTIVE OF THE STUDY: To evaluate in patients affected with PHPT the prevalence of C utilizing a validated questionnaire and the current prevalence of C compared to that observed in the past and to evaluate the relationship between C and the severity of PHPT. METHODS: 55 outpatients affected with PHPT, admitted to our Department of Internal Medicine and Medical Specialities in the years (2006-2009) were studied (group 1: 50 postmenopausal women and 5 men, mean age 61.9 +/- 9.4 years), together with 55 sex and age matched controls (group 2). Also considered were a group of PHPT patients observed, in the same ambulatory, during the years '70-'80 (group 3). A questionnaire, Rome II criteria, was administered and used to define C, whereas only anamneses were used to define C in group 3. RESULTS: The prevalence of C in patients with PHPT was 21.8% in group 1 vs 12.7% in group 2 (n.s.) and 32.7% in group 3. There is a decreasing trend in the prevalence of C in patients with PHPT as observed from 1970-89 to 2006-2009 (p < 0.05). The reduction of C was associated together with a significant reduction in the serum calcium level (p < 0.001). The presence of C vs its absence in patients with PHPT is characterized by higher values of calcemia (p < 0.001), ionized calcium (p < 0.001), and parathyroid hormone (p = 0.019). CONCLUSION: The actual prevalence of C in patients with PHPT is not significantly different from that found in the control group and is decreasing with respect to the past years. Moreover, C seems to be associated with the severity of the disease rather than with the diagnosis of PHPT per se.

Sporadic and hereditary primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, particularly frequent in post-menopausal women. It is characterized by hypercalcemia with inappropriately high spontaneous plasma PTH. Singlegland adenoma is the most common cause (75- 85%). PHPT is usually a sporadic disease but in approximately <5% of cases, a familial hyperparathyroid syndrome is diagnosed. Familial hyperparathyroidism is a clinically and genetically heterogeneous group of disorders including: multiple endocrine neoplasia (MEN) type 1, MEN type 2A, MEN4, benign familial hypocalciuric hypercalcemia, neonatal severe hyperparathyroidism, hyperparathyroidism-jaw tumor syndrome, and familial isolated hyperparathyroidism. These syndromes show mendelian inheritance patterns and the main genes for most of them have been defined. The classic form of PHPT, which presents with hypercalcemia, kidney stones, and bone disease, is no longer common. Currently, there is an increasing interest in the subtle manifestations of PHPT, particularly the cardiovascular and neuropsychiatric manifestations. Parathyroidectomy is the definitive cure for PHPT even though patients with the asymptomatic form of the disease can be followed conservatively.

Relation of adiponectin, visfatin and bone mineral density in patients with metabolic syndrome.

BACKGROUND: Adipose tissue has been suggested to influence bone density and metabolism through the effect of some adipokines. However, whether adiponectin and visfatin may correlate with bone metabolism is still unclear. AIM: The aim of this study was to investigate the relationship of adiponectin and visfatin with bone density in patients with metabolic syndrome (MS). SUBJECTS: We enroled 72 consecutive patients with MS (25 males, 47 females; mean age 58.14±11 yr) and 40 control subjects. METHODS: Plasma adiponectin and visfatin levels were measured. Bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry (DXA) at the level of lumbar spine L2-L4 (BMD L2-L4) and femoral neck (BMD-Fn). RESULTS: MS patients had higher plasma visfatin and lower adiponectin levels than controls, (p<0.01 for both). Adiponectin was negatively correlated with BMD-Fn and BMD L2-L4 (r=-0.20, r=-0.24, respectively; p<0.05 for both) whereas plasma visfatin levels were positively correlated to BMD L2-L4 only in men (r=0.44; p<0.05). CONCLUSIONS: Our study shows that adiponectin and visfatin are oppositely associated with BMD. Although the mechanisms behind these correlations are unclear, a modulation of bone metabolism by these adipokines can be suggested.

Hyperhomocysteinemia: a biochemical link between bone and cardiovascular system diseases?

Homocysteine (HCY) is a sulfur-containing amino acid involved in two metabolic pathways, catalized by cystathionine-B-synthase and methionine synthase, depending on vitamin (vit) B6, B12, and folate levels and enzymatic activity of methylenetetrahydrofolate. High HCY levels (HHCY) are associated with cardiovascular (CV) and bone diseases, in particular osteoporosis (OP)/hip fracture. As regards the mechanisms involved in the link between HHCY, CV diseases (CVD), and OP, it has been proposed the role of lysyl-oxydase inhibition that might interfere with collagen crosslink formation. Some studies suggested the dysregulation of the osteoprotegerin/receptor activator of nuclear factor-kappaB (RANK) ligand/RANK axis, others the involvement of oxidative stress. These mechanisms may act both on bone and CV system, but whether the common denominator is HCY itself or HCY is merely a marker, remains to be clearly established. Folate, vit B6, and B12 supplementation is associated with HCY reduction, but is unable to certainly reduce the incidence of OP/fracture and CVD, probably because, in the majority of patients, HCY is only moderately increased.

Biochemical markers in glucocorticoid-induced osteoporosis.

Following the introduction of corticosteroids as therapeutic agents in the 1950s, their use has been expanded so that today glucocorticoids are widely used. There are few studies in the literature directly aimed at describing the changes of bone markers following glucocorticoid administration. The interpretation of some of these investigations may be hampered by a number of confounding factors, whose influence is not always taken into consideration. In general, the effects of glucocorticoid administration are represented by a reduction in bone formation markers (particularly considering serum osteocalcin levels) and a trend to an increase or no change in bone resorption markers. The inconsistency of this last finding may be related to the time at which the observation is carried out and to the marker employed.

Skeletal turnover, bone mineral density, and fractures in male chronic abusers of alcohol.

BACKGROUND: Chronic alcohol abuse is a risk factor for osteoporosis and fractures, whose pathogenesis is still unclear. We investigated the influence of alcoholism and other risk factors on calcium and skeletal metabolism, bone mineral density (BMD), and fractures. MATERIALS AND METHODS: In 51 chronic male alcoholics without liver failure and 31 healthy controls, serum total and ionised calcium, phosphate, creatinine, 25-hydroxy vitamin D (25OHD), PTH, total (ALP) and bone-specific (BALP) alkaline phosphatase, osteocalcin (BGP), carboxy-terminal telopeptide of type I collagen (beta-CTx), osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) were assessed. In patients only, we also measured serum testosterone, 17-beta estradiol, LH, and IGF-I. BMD was measured by dual energy x-ray absorptiometry at lumbar spine (LS-) and femur [neck (FN-) and total hip (TF-)]. Vertebral fractures were identified by a semiquantitative method on thoraco-lumbar spine x-ray, non-vertebral fractures (as life-style factors) by history. RESULTS: Alcoholics were leaner, had significantly higher ALP and BALP, and lower BGP and 25OHD levels than controls. No significant difference in other calcium and bone metabolism parameters was found. OPG/RANKL ratio was significantly higher in alcoholics. Beta-CTx negatively correlated with abuse duration. OPG positively correlated with daily alcohol assumption and with indexes of liver cytolysis. Though LS-, FN- and TF-BMD of alcoholics and controls did not significantly differ, patients had a much higher prevalence of vertebral fractures. The same was found considering both vertebral and non-vertebral fractures. CONCLUSIONS: Ethanol-induced skeletal damage seems mainly dependent on negative effects on bone formation. Lifestyle factors and traumas likely contribute to the high fracture incidence of alcohol abusers, independently of BMD.

Metabolic bone diseases during long-term total parenteral nutrition.

Long-term total parenteral nutrition (TPN) is a procedure commonly applied to patients with advanced forms of intestinal malabsorption. Among TPN complications, bone metabolic diseases, such as osteoporosis and osteomalacia, are a common finding. Initially considered to be a manifestation of aluminium toxicity which followed massive contamination with the element of the solutions used in TPN, metabolic osteopathy during TPN is currently considered a multiform syndrome, with a multifactorial pathogenesis, which may manifest itself with vague or clear clinical pictures. In this review, we analyse clinical, pathogenetic, and therapeutic aspects of the most common bone metabolic diseases in patients undergoing long-term TPN.

Expression of potassium channel isoforms mRNA in normal human adrenals and aldosterone-secreting adenomas.

Increased aldosterone secretion has been found in a mouse lacking the KCNE1 gene which codes for a regulatory protein of the KCNQ1 gene product, forming the channel for the outward rectifying delayed K+ current. Abnormalities in proteins regulating the K+ fluxes across membranes may be responsible for aldosterone-secreting adenomas (aldosteronomas) also because K+ channels are involved in cell growth. Normal and adenomatous adrenal samples and NCI-H295 cell line were used to: a) evaluate KCNE1 and KCNQ1 gene expression, b) sequence the full length cDNAs of KCNE1 and both KCNQ1 isoforms. These differently spliced KCNE1 and KCNQ1 mRNAs were expressed in adrenal tissue. In contrast, KCNQ1 isoform 2 mRNA was not expressed in kidney control tissues and NCl-H295 cell line. NCI-H295 cell line also had a significantly lower expression of KCNQ1 isoform 1 mRNA than normal adrenals and aldosteronomas. We did not find any somatic mutations in the coding sequences of both genes. This different expression pattern of KCNQ1 isoforms in NCI-H295 cell line with the lack of the mRNA for the dominant-negative KCNQ1 isoform 2 supports the involvement of voltage-gated K+ channel in cell proliferation.

Cyclical changes of vertebral body heights and bone loss in healthy women after menopause.

Annual changes in vertebral body heights (VHs) and lumbar bone mineral density (LBMD) were evaluated in 120 healthy pre- and post-menopausal women aged 45-74 years. Subjects were divided into groups according to menstrual status and years since menopause (YSM). Vertebral heights were evaluated, using radiological morphometry as the sum of anterior vertebral body heights (AVHs) from T4 to L5 at baseline and exactly 12 months later. Results indicate that the sum of VHs is inversely correlated with advancing age, and the decrease in VHs is not a constant process over time but rather exhibits cyclical damping oscillations. When log-linear trend of VH decrease was transformed into a constant considering annual percentage changes, the presence of a cyclical component of 7 years was evident. Employing a harmonic regression model, the cyclical component was also statistically significant on baseline data. The cyclical decrease of VHs corresponds to an analogous cyclical behavior of LBMD values. These results suggest that a lack of estrogen acts as a synchronizer on bone remodeling, triggering a latent cyclical rhythm of bone loss, accompanied by cyclical bone microarchitecture deterioration and consequent vertebral body deformities, which after menopause persists throughout life. The existence of a chronobiological rhythm of bone loss and trabecular bone strength reduction at vertebral level after menopause, if confirmed, could have important clinical implications.

Superiority of alfacalcidol compared to vitamin D plus calcium in lumbar bone mineral density in postmenopausal osteoporosis.

In a randomized multicenter, double-blind, double-dummy, parallel group study a comparison of the efficacy and safety of 1 microg alfacalcidol to 880 IU vitamin D plus calcium carbonate (1 g calcium) once daily per os was performed on 148 postmenopausal osteoporotic Caucasian patients with normal vitamin D serum levels for 18 months. Bone mineral density (BMD) was measured at baseline, 12 and 18 months. Safety parameters were followed during the entire study period. Sixty-nine (90.8%) in the alfacalcidol group and 67 (93.1%) in the vitamin D group were included in the ITT analysis. Lumbar BMD in the alfacalcidol group increased by 0.017 g/cm2 (2.33%) and 0.021 g/cm2 (2.87%) from baseline (P<0.001) at 12 and 18 months, respectively, whereas in the vitamin D plus calcium group the increase was 0.005 g/cm2 (0.70%) from baseline (N.S.) at both 12 and 18 months. The higher changes from baseline in the alfacalcidol group, as compared to the changes in the vitamin D plus calcium group at both 12 and 18 months, were found to be statistically significant (P=0.018, 0.005). A small increase of mean femoral BMD was achieved in both groups (N.S.). Adverse events were similar in both groups. No significant differences were noted between the groups in serum calcium. In conclusion, alfacalcidol was found to be superior in significantly increasing lumbar BMD as compared to vitamin D plus calcium while safety characteristics were found to be similar in both treatments.

[Primary hyperparathyroidism]. / Iperparatiroidismo primitivo.

Primary hyperparathyroidism (PHPT) is characterized by excessive PTH secretion in respect to calcium homeostasis needs, due to parathyroid adenoma (80% of cases), hyperplasia (15-20%), or carcinoma (1-2%). In familial forms of PHPT, several mutations have an established role: menin gene for MEN type 1, RET for MEN type 2a, calcium-sensing receptor gene for familial hypocalciuric hypercalcemia, parafibromin gene for PHPT-jaw tumour and carcinoma. Etiology of sporadic adenomas (80% of PHPT cases) is less defined, being most commonly found a mutation of menin gene or activation of PRAD1 oncogene. In recent years, the classical features of the disease became less common. Typically, bone involvement is now represented by a reduced bone mass at skeletal sites more rich in cortical tissue. Prominently trabecular skeletal sites are relatively spared, because of the anabolic effects of a slight PTH excess on trabecular tissue. PHPT patients may have increased fracture risk, though it is not clear why bone damage is more severe in a subgroup of patients. Clinical features of hypercalcemia may be fatigue, anorexia, thirst, and polyuria. Vague neurological and psychiatric symptoms, such as weakness, anxiety, depression, paresthesias, and muscular cramps may ameliorate after parathyroidectomy. Recent reports indicate increased cardiovascular mortality in PHPT patients. Diagnosis is based on the detection of hypercalcemia, together with inappropriately high serum PTH levels. Preoperative localization of the diseased glands is mandatory in persistent or recurrent PHPT, as like as when minimally invasive surgery is planned. High resolution ultrasonography and SPECT double-phase 99m Tc-sestamibi scintigraphy are the most commonly employed techniques. Intraoperatory PTH assay may confirm successful surgery when serum concentrations decrease more than 50%. Surgical therapy is indicated in patients with renal or skeletal complications, such as in those with previous parathyrotoxic crisis. Many surgeons in recent years adopted minimally invasive parathyroidectomy. Medical treatment is an option for patients unwilling or unfitted for surgery because of severe concomitant diseases. Employed therapy includes estrogens, SERMs, bisphosphonates and calcimimetics.

Ambulatory monitoring of blood pressure (AMBP) in patients with primary hyperparathyroidism.

The purpose of our study was to evaluate the behaviour of blood pressure (BP) by ambulatory monitoring of blood pressure (AMBP) in 53 patients with primary hyperparathyroidism (PHPT) compared to 100 essential hypertensive (EH) and 31 healthy subjects (HS). The correlations between calcium-phosphorus metabolism and haemodynamic parameters in all groups are included in the study. AMBP was performed using the oscillometric technique (Space-Labs, 90207, Redmond, WA, USA) and the following AMBP parameters were evaluated: average day time systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) (when awake), average night time SBP, DBP and HR (when asleep) and average 24-h-SBP, DBP and HR. The definition of 'dipper' or 'non-dipper' subjects was established if night time SBP and DBP fall was >10% and <10%, respectively. In total, 25 PHPT patients (47.2%) were hypertensive (HT-PHPT) and 28 PHPT (52.8%) were normotensive (NT-PHPT). Mean 24-h-SBP and DBP obtained by AMBP was higher in HT-PHPT (P < 0.05) and EH (P < 0.05) than in NT-PHPT and HS. The multiple linear regression has shown that in PHPT-HT patients ionized calcium is an independent factor for the rise of 24-h-DBP values (r: 0.497; P < 0.05) and daytime DBP values (r: 0.497; P < 0.05). In 56% of HT-PHPT patients there is an absence of physiological BP nocturnal fall ('non-dipper'), which is statistically significant (P < 0.05) compared with 'non-dipper' EH patients (30%). In conclusion, in our study the prevalence of hypertension in PHPT was 47%. AMBP revealed that the 'non-dipping 'pattern was much higher in HT-PHPT patients in respect to EH patients.

Dehydroepiandrosterone sulfate and bone resorption rates as reflected by serum levels of C-terminal telopeptide of type I collagen: a study in healthy men.

Sex steroid hormones contribute to the physiological regulation of bone turnover in males. To address this issue, we investigated serum estradiol (E2), total testosterone (T), and DHEAS concentrations, along with serum levels of carboxy-terminal telopeptide of type I collagen (sCTx), in a sample of 76 healthy men aged 23 to 87. The concentration of sCTx declined with age. Both T and DHEAS, at variance with E2, showed a significant age-related decline. T, DHEAS and sCTx significantly (p<0.01) correlated with each other. DHEAS and T were significantly associated after correcting for age (r=0.35, p=0.002) or body mass index (r=0.65, p<0.0001). DHEAS, but not T, significantly correlated with sCTx after correcting for age (r=0.26, p=0.026, and r=0.20, p=0.08, respectively). Stepwise multiple regression analysis showed that only DHEAS (but not T or E2) was a significant independent predictor of sCTx (p=0.0001). Our results show that adrenal androgens play a crucial role in regulating bone resorption in aging men.

Acute hyperinsulinemia is associated with increased plasma adrenomedullin concentrations in uncomplicated obesity.

OBJECTIVE: Adrenomedullin (AM) is a potent hypotensive peptide which may be implicated in the insulin regulatory system. Acute hyperinsulinemia exerts no influence on plasma AM in normal subjects while no data on obese subjects has been reported. PURPOSE: The aim of the study was to investigate the effect of acute hyperinsulinemia on the plasma AM concentration in patients with uncomplicated obesity. RESEARCH METHODS: We measured the plasma AM levels in 23 obese subjects (BMI 41.9 +/- 9.8 kg/m2), 21 females and 2 males (mean age 31 +/- 7.2 years), before and during a euglycemic hyperinsulinemic clamp. The control group consisted of 43 healthy subjects (HS) (22 males and 21 females; mean age 38 +/- 12 years; BMI 23.3 +/- 3.2 kg/m2). RESULTS: Baseline plasma AM was found to be higher in obese subjects (20.4 +/- 8.4 pg/ml) than in normal subjects (11.3 +/- 0.8 pg/ml) (p < 0.001). A significant increase in the plasma AM levels was observed in obese subjects during acute hyperinsulinemia (from 20.4 +/- 8.4 pg/ml at 0 min to 26 +/- 8.9 pg/ml at 120 min, p < 0.02). Plasma AM concentrations were significantly correlated with insulin levels at 30 min (r = 0.44; p = 0.04) and 120 min (r = 0.40, p = 0.05) during the clamp. DISCUSSION: In conclusion, acute hyperinsulinemia induced a significant increase in the plasma levels of AM in uncomplicated obese subjects. Hyperinsulinemia may, at least in part, regulate levels of AM in obesity, explaining the high levels of the peptide in these subjects.

Plasma levels of adrenomedullin in patients with adrenoleukodystrophy/adrenomyeloneuropathy.

BACKGROUND/AIMS: Adrenomedullin (AM) is a recently purified hypotensive peptide and its encoding gene has been sequenced from a human pheochromocytoma. High levels of AM have been shown in Addison's disease (AD). X-linked adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN) is a peculiar adrenal insufficiency due to an accumulation of very-long chain fatty acid in adrenal cells and it is very often associated with a devastating demyelination of the central nervous system. METHODS: We studied the AM plasma levels of 22 patients with ALD/AMN (18 with hypoadrenalism, ALDa, and 4 with normal adrenal function, ALDb) and compared them with 18 males with classical AD and 16 normal male subjects. All patients with hyposurrenalism were studied before treatment with hydrocortisone. RESULTS: Both patients with ALD/AMN and AD showed increased levels of AM and all of them showed a significant difference from the control group (p < 0.0001). The plasma renin activity was higher in all patient groups than in the control group (p <0.001 ALDa, ALDb and AD vs. control group). The aldosterone levels were higher in ALDa and ALDb groups than AD (ALDa vs. AD p < 0.01; ALDb vs. control group p < 0.05; AD vs. controls p < 0.01). ACTH plasma levels were higher in ALDa and AD than ALDb and the control group (ALDa vs. AD not significant while ALDa and AD vs. control p <0.0001). CONCLUSIONS: Our data indicate that plasma AM levels in ALDa, ALDb and AD are higher than controls. These results were previously described in untreated AD. While classical AD patients show complete adrenal insufficiency (both mineralocorticoid and glucocorticoid defects), ALD/AMN patients show a less compromised glomerular function, indicating that AM is not completely correlated with mineralocorticoid insufficiency, and that the exact mechanism responsible for the increased AM levels in ALD/AMN is still unknown.

Cardiovascular disease and osteoporosis.

Cardiovascular disease (CVD) and osteoporosis (OP) are public health problems with numerous epidemiological links and important economic consequences. Recent studies have demonstrated that CVD and cardiovascular mortality are associated with reduced bone mineral density (BMD) and bone fractures. These two conditions may be sustained by similar or common pathophysiological mechanisms and risk factors. There are several matrix proteins, such as type 1 collagen, proteoglycan, osteopontin, and osteonectin, which are found in bone and vascular matrix components. Matrix proteins play an important role both in bone formation and in the development of atherosclerosis. Estrogens also play a role in both CVD and OP through their effects on cytokines, such as IL-1, IL-6 and TNF-alpha and osteoprotegerin (OPG). The lack of estrogens induces an increase in these cytokines and a decrease in OPG, both implicated in the mechanisms of bone loss and atherogenesis. An additional link between CVD and OP seems to be related to the action of some drugs, such as bisphosphonates, statins and raloxifene. Several studies suggest that the mechanism of action of these drugs at cellular level may not be mutually exclusive, acting either in bone or in atherosclerotic plaque. However, further studies are necessary to define the relationship between CVD and OP more specifically and to understand the complex interaction of similar or common risk factors and genetic or molecular determinants.

Increased plasma levels of adrenomedullin, a vasoactive peptide, in patients with end-stage pulmonary disease.

AIM: To study adrenomedullin (AM) plasma levels in patients with severe lung disease and to analyze the relationship between AM and heart changes, hemodynamics and blood gases. METHODS: Case control study of 56 patients (36 men, 20 women) with severe lung disease and 9 control subjects (7 men, 2 women). Patients with end-stage pulmonary disease, including chronic obstructive pulmonary disease (COPD, n=11), cystic fibrosis (CF, 26), idiopatic pulmonary fibrosis (ILD, n=9), and idiopatic pulmonary arterial hypertension (PAH, n=10), who were evaluated for lung trasplantation between January 1997 and September 2000, and nine patients who underwent lung surgery for a solitary benign nodule. AM plasma levels in pulmonary artery (mixed venous blood, vein) and aorta or femoral artery (arterial, art), art and vein blood gases, pulmonary hemodynamics, systemic hemodynamics, two-dimensional transthoracic echocardiography and echo-Doppler study. RESULTS: Plasma AM (art and ven) levels were higher among patients' group compared to the controls (AMart p<0.02 and AMven p<0.04) for CF, ILD, PAH (AMart, pg ml(-1) Controls 13.7+/-3.6, COPD 22.8+/-6.2, CF 28.1+/-11.4, ILD 34.1+/-14.3, PAH 35.1+/-18.9; AMven, pg ml(-1) Controls 14.2+/-4.8, COPD 28.1+/-12.6, CF 31.7+/-14.1, ILD 38.7+/-16.5, PAH 40.1+/-4.4). We found with a trend towards higher concentration in ILD and PAH patients compared to COPD and CF but no statistical significant differences. Mixed-venous AM was higher than arterial AM in all groups resulting in AM uptake (AMPulmUp pg min(-1) Controls 4.8+/-22.6, COPD 21.1+/-44.9, CF 20.6+/-45.1, ILD 23.7+/-38.5, PAH 29.9+/-49.7). The univariate analysis showed a weak but significant correlation between AMart and mean systemic arterial pressure, heart rate, mean pulmonary arterial pressure and systemic vascular resistance. In the multivariate analysis, four variables emerged as independent factors of AMart including mean pulmonary arterial pressure, heart rate, mean systemic arterial pressure and left ventricular diastolic diameter (F=8.6, p<0.00001, r=0.60, r2=0.32). A similar weak correlation was apparent between AMven, systemic vascular resistance, and mean pulmonary arterial pressure. The results of multivariate analysis identify right atrial enlargement, mean right atrial pressure, heart rate and left ventricular dimensions as the only independent variables related to AMven (F=4.3, p<0.0004 r=0.56, r2=0.26). AM pulmonary uptake was significantly correlated with AMven (r=0.65), but not with hemodynamic, blood gas and echocardiographic variables. CONCLUSIONS: AM plasma levels are elevated in patients with severe lung disease in face of a preserved pulmonary uptake. These results suggest that the high AM plasma levels in patients with severe lung disease are not caused by a reduced pulmonary clearance, instead suggesting a systemic production.

Adrenomedullin immunoreactivity tissue distribution in parathyroids of the patients with primary hyperparathyroidism.

Adrenomedullin (ADM) is a new potent vasorelaxant peptide identified originally in extracts of pheochromocytoma, and is widely distributed within the tissue. Although histopathological studies have demonstrated the presence of ADM-immunoreactivity (ir-ADM) in some human neuroendocrine tumors (such as insulinoma, pituitary adenoma, and gastrointestinal neuroendocrine tumors), data on the presence of ADM in normal and pathological parathyroid gland are not available. Plasma AM concentrations were recently reported to be elevated in patients with PHP (primary hyperparathyroidism). The aim of our study was to determine tissue distribution of ir-AM in 34 patients with PHP (27 female and 7 male, mean age 50 +/- 6 years) undergoing surgery. Six normal parathyroid samples incidentally found during thyroidectomy for neoplastic diseases and ten sections of human rectus abdominis muscle tissue were used as controls (C). Adenomatous parathyroids were found in 22 PHP and hyperplastic parathyroids in twelve PHP patients. Four hyperplastic parathyroids were found in three PHP patients and three parathyroids in 10 PHP patients. Eight parathyroids revealed a prevalent diffuse growth pattern and four showed a prevalent nodular growth pattern. Immunohistochemical ADM expression was seen in seven of twelve (58.3 %) hyperplastic parathyroids and in fourteen of twenty-two (66.6 %) adenomatous glands. Parathyroid chief cells showed strong cytoplasmatic staining, whereas oncocytic cells showed a faintly aspecific cytoplasmatic staining. Normal parathyroids were negative for ir-ADM. In conclusion, we found the presence of ADM in parathyroid chief cells of PHP patients using immunohistochemistry in our study.