Giuseppe Costanza

Age, homocysteine, and oxidative stress: relation to hypertension and type 2 diabetes mellitus.

Objectives: Hyperhomocysteinemia and oxidative stress are independent risk factors for cardiovascular events, which occur more frequently in old age. We evaluated these parameters in relation to age and the presence of hypertension and type 2 diabetes mellitus. Methods: Two hundred eighty-two subjects (female/male: 142/140; 141 were >65 years and 141 were <65 years; mean age 73.9 ± 6.6 years and 52.5 ± 8.2 years, respectively) were randomly recruited from those attending our institution. Blood pressure, anthropometric parameters, oxidative stress parameters (reactive oxygen species [ROS] and malondialdehyde [MDA]), and homocysteine levels were evaluated in participants. Results: Homocysteine (2.9 ± 0.06 vs. 2.3 ± 0.03 µmol/L, p < 0.001) and oxidative stress (ROS: 10.8 ± 0.3 vs. 8.1 ± 0.3 mmol/L, p < 0.001; MDA: 1.62 ± 0.05 vs. 1.21 ± 0.05 nmol/mL, p < 0.001) were significantly higher in older vs. younger subjects without hypertension or diabetes. However, homocysteine and MDA were not significantly different in older vs. younger hypertensive subjects (homocysteine: 3.0 ± 0.03 vs. 2.9 ± 0.04 µmol/L, p  =  NS; MDA: 1.7 ± 0.07 vs. 1.4 ± 0.06 nmol/mL, p  =  NS) and in older vs. younger diabetic hypertensive subjects (homocysteine: 3.02 ± 0.05 vs. 2.9 ± 0.05 µmol/L, p  =  NS; ROS: 10.7 ± 0.7 vs. 9.7 ± 0.8 mmol/L, p  =  NS; MDA: 1.6 ± 0.10 vs. 1.5 ± 0.12 nmol/mL, p  =  NS). Conclusions: Aging is accompanied by elevated homocysteine and oxidative stress levels similar to those observed in younger subjects with hypertension or diabetes mellitus, independent of age. Hence, these conditions appear to accelerate the age-dependent increase in homocysteine and oxidative stress.

AZITHROMYCIN IN AN OLDER WOMAN WITH DIABETIC GASTROPARESIS

Diabetic neuropathy is a common chronic complication of diabetes and cause of significant morbidity and mortality, because it may involve the autonomous and peripheral nervous systems. Autonomic diabetic neuropathy is a challenging chronic complication of long-standing diabetes manifested with hypotension, syncope, gastroparesis, diarrhea, constipation, bladder dysfunction, sexual dysfunction, cardiac arrest, and/or sudden death. We present a case of diabetic gastroparesis in an older woman. The patient was an 83-year-old woman with a 40-year history of type 2 diabetes who was admitted with hypoglycemia, malnutrition, persistent vomiting, and obstinate constipation. After several unsuccessful attempts with different therapies, we administered intravenous azithromycin (500 mg/day). After 3 days of treatment, vomiting was resolved and the patient evacuated normal feces, with notable improvement in the general conditions and metabolic control. Because diabetic gastroparesis frequently is difficult to manage clinically and there are few beneficial therapeutic choices available at present, the macrolide antibiotic azithromycin, which has strong prokinetic properties, may be a useful option in the treatment of this complex condition.

MAGNESIUM METABOLISM IN INSULIN RESISTANCE, METABOLIC SYNDROME, AND TYPE 2 DIABETES MELLITUS

Magnesium plays a key role in regulating insulin action, insulin-mediated glucose uptake, and vascular tone. Intracellular magnesium depletion may result in a defective tyrosine—kinase activity at the insulin receptor level, in a postreceptorial impairment in insulin action, and clinically in a worsening of insulin resistance. Intra- and extracellular alterations of magnesium metabolism have been identified in clinical states characterized by insulin resistance, such as metabolic syndrome, hypertension, altered glucose tolerance, type 2 diabetes, and aging. Several studies, from our and other’s groups, have confi rmed the clinical relevance of alterations of magnesium homeostasis in these conditions and have highlighted the importance of an accurate definition of the magnesium status. While measurements of total serum magnesium levels have been proven inadequate for this purpose because important magnesium depletions are required before total serum level decreases, two technologies, 31P nuclear magnetic resonance (31P-NMR) spectroscopy and magnesium-specifi c ion-selective electrodes, that, respectively, measure intracellular and extracellular free levels of magnesium, have a higher sensitivity in detecting magnesium deficits. A number of evidences have confirmed that magnesium supplementation is indicated in conditions associated with magnesium deficit, although well-designed therapeutic trials with oral magnesium supplements to study the beneficial effects in metabolic syndrome and in type 2 diabetes are needed.

Diuretic Therapy in Old Patients

The administration of diuretics is indicated in several clinical conditions characterized by more or less severe water and salt retention (congestive heart failure, non-compensated liver cirrhosis, renal syndromes etc.), or in cases in which water and sodium depletion is supposed to improve some pathophysiological aspects of clinical symptoms (e. g. as background treatment in arterial hypertension, or as emergency treatment in left ventricular failure.