Ceruso D

Relationship between plasma leptin levels and the tumor necrosis factor-α system in obese subjects

OBJECTIVE: To evaluate the relationship between plasma leptin and the tumor necrosis factor-α (TNFα), TNF receptor p60 (TNF-R1) and TNF receptor p80 (TNF-R2) concentrations in obese subjects.DESIGN: Case-control study.SETTING: Outpatient’s Service for Prevention and Treatment of Obesity at the University Hospital.MEASUREMENTS: Body mass index (BMI), waist circumference, hip circumference, waist-to-hip ratio (WHR), fasting plasma glucose, fasting plasma insulin, homeostasis model assessment of insulin resistance (HOMA IR), plasma leptin, TNF α, TNF-R1 and TNF-R2 concentrations were evaluated in obese subjects (n=42) and in age- and gender-matched, lean healthy controls (n=16).RESULTS: In obese subjects, fasting plasma glucose and insulin, HOMA IR, plasma leptin, TNFα, TNF-R1 and TNF-R2 concentrations were significantly higher than in controls. Furthermore, females showed higher leptin, TNF-R1 and TNF-R2 plasma concentrations compared to males, in both control and obese subjects. In control subjects, plasma leptin concentrations showed a direct correlation with BMI (r=0.74, P<0.001), hip circumference (r=0.94, P<0.001), TNF-R1 (r=0.79, P<0.001) and TNF-R2 (r=0.64, P<0.01), and a negative correlation with WHR (r=−0.58, P<0.05). In obese subjects, we found a direct correlation between plasma leptin concentrations and BMI (r=0.67, P<0.001), hip circumference (r=0.66, P<0.001), fasting glucose (r=0.37, P<0.05), fasting insulin (r=0.31, P<0.05), HOMA IR (r=0.38, P<0.05), TNF-R1 (r=0.71, P<0.001) and TNR-R2 (r=0.66, P<0.001), while a negative correlation was found between circulating leptin and WHR (r=−0.44, P<0.01). In multivariate analysis, plasma leptin concentrations were significantly associated with BMI (P=0.015) and gender (P=0.047) in the control group, while in obese subjects, plasma leptin showed a significant association with BMI (P=0.019) and TNF-R1 (P=0.012).CONCLUSIONS: Our results are consistent with the hypothesis that the TNFα system could be involved in the regulation of plasma leptin concentrations in obese subjects.

Changes in plasma, erythrocyte, and platelet magnesium levels in normotensive and hypertensive obese subjects during oral glucose tolerance test

We evaluated the 75-g oral glucose tolerance test (OGTT)-induced modifications in glucose, insulin, and norepinephrine plasma concentrations, and in plasma, erythrocyte, and platelet magnesium levels in two groups of obese subjects (normotensive obese, NT-Ob, N = 19; hypertensive obese, HT-Ob, N = 15), and in a group of healthy control subjects (N = 12). During OGTT we detected a reduction in plasma magnesium concentrations and an increase in erythrocyte and platelet magnesium levels in the controls, whereas in both normotensive and hypertensive obese subjects, there was a reduction in plasma, erythrocyte, and platelet magnesium levels. Furthermore, no statistically significant difference was detected among the groups studied as regards delta-plasma magnesium. On the other hand, delta-erythrocyte magnesium and delta-platelet magnesium were negative in the NT-Ob (delta-erythrocyte magnesium: -0.24+/-0.08 mmol/L; delta-platelet magnesium: -0.49+/-0.09 micromol/10(8) cells) and HT-Ob (delta-erythrocyte magnesium: -0.20+/-0.10 mmol/L; delta-platelet magnesium: -0.50+/-0.11 micromol/10(8) cells) groups, and positive in control subjects (delta-erythrocyte magnesium: 0.40+/-0.08 micromol/L; delta-platelet magnesium: 0.47+/-0.09 mmol/ 10(8) cells). Finally, a direct correlation was found between delta-norepinephrine and delta-erythrocyte magnesium (r = 0.80, P < .01) in the control group, and a negative correlation was detected between delta-norepinephrine and delta-platelet magnesium (r = -0.58, P < .05) in the HT-Ob group. Our results seem to indicate that the insulin resistance status, the hyperglycemia, and the disregulation of the adrenergic system in obese subjects could be involved in the pathogenesis of the magnesium homeostasis impairment observed in the obese subjects.

Magnesium levels in plasma, erythrocyte, and platelet in hypertensive and normotensive patients with type II diabetes mellitus

The authors, by means of a recently introduced method, evaluated the intraplatelet concentrations of magnesium in 45 normotensive patients with type II diabetes mellitus, in 45 hypertensive diabetics and in 15 healthy controls. They also evaluated plasma and erythrocyte concentrations of the cation through direct current plasma spectrometer. Both normotensive and hypertensive diabetics showed a reduction in plasma, erythrocyte, and platelet concentrations of magnesium compared to controls. On the contrary, no significant difference was found between hypertensive and normotensive diabetics with regard to plasma and erythrocyte magnesium, whereas intraplatelet assay of the ion pointed out significantly lower concentrations of magnesium in hypertensive compared to normotensive patients (56.4±9.0 vs 60.7±10.2 μg/108 cells-p<0.05). The authors believe that intraplatelet assay of magnesium may be the most reliable method for the evaluation of the cation in hypertensive diabetics, probably because platelets share common features with smooth muscle cells, including the α-2-adrenoceptor cyclase system and a coupling mechanism concerning the calcium-dependent contraction.

Antihypertensive drug therapy and hypoglycemia in elderly diabetic patients treated with insulin and/or sulfonylureas

We performed this case–control study to evaluate the risk of hypoglycemia associated with the use of antihypertensive drugs in older hospitalized diabetic patients treated with sulfonylureas and/or insulin. All diabetic patients admitted during 4 months in 1988, 1 month in 1991, 4 months in 1993 and 4 months in 1995 (n = 3477, mean age 71.4 ± 0.2 years, 1542 males and 1935 females) were enrolled in the study. During the four annual surveys 86 patients (mean age 71.1 ± 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital stay. The patients who presented hypoglycemia were less frequently users of sulfonylureas and more frequently users of a combination of insulin and sulfonylureas. Use of antihypertensive drugs was similar in the two groups studied, and among potentially interacting drugs considered in the analysis, sulfonamides were more frequently used in patients who experienced hypoglycemia. Moreover, patients with hypoglycemia used a higher number of drugs, had a longer length of stay and had a greater prevalence of hypoglycemia as admission problem. Finally, although not significant, liver and renal diseases were more frequent among patients with hypoglycemia. In the multivariate analysis, contemporary use of insulin and sulfonylureas, liver disease and length of stay were significantly associated with hypoglycemia, while none of the antihypertensive drugs showed a significant association with the occurrence of hypoglycemia during hospital stay. Our results indicate that antihypertensive drugs do not increase the risk of hypoglycemia in elderly diabetic patients.

Plasma interleukin-2 levels and thyroid function in elderly patients with nonthyroidal illness

To determine whether interleukin-2 (IL-2) plasma concentrations are modified in patients with nonthyroidal illness (NTI) and thyroid function alterations, we measured plasma concentrations of T(3), T(4), free T(3) (FT(3)), free T(4) (FT(4)), TSH, and IL-2 in 34 elderly NTI patients and in 25 age- and sex-matched healthy controls. IL-2 was detectable in 11 of the 34 patients. Patients with detectable IL-2 plasma levels had significantly lower plasma T(3) and FT(3) concentrations when compared to those with undetectable IL-2. Moreover, IL-2 plasma levels were positively correlated to reverse T(3) (rT(3)), (r(S)=0.67, P<0.05), and negatively to FT(3) concentrations (r(S) =-0.64, P<0.05). These observations suggest that some of the alterations in thyroid hormone levels seen in NTI are associated with elevated plasma concentrations of IL-2.

Reduced intraplatelet magnesium concentrations in elderly patients with non-insulin dependent diabetes mellitus (NIDDM).

Intraplatelet magnesium concentrations were evaluated in 50 non-insulin dependent diabetes mellitus (NIDDM) patients divided into two groups of 25 each (<60 or >65 years) and in a control group of 30 healthy subjects, divided into two age-matched subgroups of 15 each. In all patients magnesium concentrations were assayed in plasma, erythrocytes and platelets by means of direct current plasma spectrometry. Plasma, erythrocyte and platelet magnesium levels in healthy elderly subjects were found to be comparable to those in the group of younger healthy subjects, whereas plasma, erythrocyte and platelet magnesium levels in diabetics were lower than in controls. The reduction in intraplatelet magnesium concentrations found in elderly diabetics was greater than in the younger diabetics. In diabetics, moreover, an inverse correlation was found between platelet magnesium and age, but not between plasma or erythrocyte magnesium and age. Our findings show that aging can influence the alterations in the metabolism and compartmentalization of magnesium determined by type 2 diabetes mellitus. This condition may underlie platelet function alterations which, in turn, can exacerbate vascular complications from diabetes.

The influence of hypercholesterolemia on some aspects of immune pattern in the elderly.

In order to investigate if age related dislipidemia was associated with immunological changes in vivo, humoral, soluble and cellular immune parameters were evaluated both in elderly with and without hypercholesterolemia and in young adults. Significantly increased IgG and IgA values were found in hypercholesterolemic aged compared to the other groups. Increased plasma neopterin levels (a pteridine generally used as a marker of macrophage activity) were reported in healthy aged subjects, whereas a lesser degree of the activation of the macrophage system was found in the hypercholesterolemic aged subjects. Compared with the young controls, an increase of interleukin 2 receptor expressing cells and of the IL-2 soluble receptors was noticeable in healthy aged subjects, whereas in hypercholesterolemic aged subjects only a minor increase of the IL-2 membrane receptor was noticed. We suggest that hypercholesterolemia may play a role in immune function in aging.

Relationship between serum erythropoietin levels and rT3, T4 concentrations in elderly patients with non-thyroidal illnesses.

Thyroid function, plasma erythropoietin and tumor necrosis factor (TNF-alpha) concentrations were measured in 28 elderly patients with chronic non-thyroidal illnesses (NTI) and in 8 healthy subjects as a control group. In the NTI group, the existence of an impairment of thyroid function has been demonstrated in about 85% of the subjects, with a lower T(3) concentration; a low T(3) syndrome with low T(3) levels and high reverse-T(3) (rT(3)) plasma concentrations could be found in 25% of the subjects. A direct correlation between erythropoietin and rT(3) and an inverse correlation between erythropoietin and T(4) were found on NTI patients with endocrine abnormalities.