The anti-inflammatory and immunological properties of SGLT-2 inhibitors

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are antidiabetic oral drugs that act on proximal renal tubules promoting renal glucose excretion. Although SGLT-2i belong to the class of hypoglycemic agents, in the last years great interest has emerged in studying their pleiotropic effects, beyond their ability to lower glucose levels.

PURPOSE

In this review we are describing the anti-inflammatory and immunological properties of SGLT-2i; furthermore, we are addressing how the mechanisms associated with the aforementioned anti-inflammatory properties may contribute to the beneficial effects of SGLT-2i in diabetes.

METHODS

A systematic search was undertaken for studies related the properties of SGLT-2i in reducing the inflammatory milieu of acute and chronic disease by acting on the immune system, independently by glycemia.

RESULTS

Recently, some data described the anti-inflammatory and immunological properties of SGLT-2 in both pre-clinical and clinical studies. Numerous data confirmed the cardio- and -renal protective effects of SGLT-2i in patients with heart failure and kidney diseases, with or without diabetes.

CONCLUSIONS

SGLT-2i are promising drugs with anti-inflammatory and immunological properties. Despite the mechanism of action of SGLT-2i is not fully understood, these drugs demonstrated anti-inflammatory effects, which may help in keeping under control the variety of complications associated with diabetes.

Anti-inflammatory effects of diet and caloric restriction in metabolic syndrome

BACKGROUND

Weight loss in patients with metabolic syndrome has positive effects on cardiovascular and type 2 diabetes risks, but its effects on peripheral cytokines and lipid profiles in patients are still unclear.

AIM

To determine the effects of diet-induced weight loss on metabolic parameters, lipids and cytokine profiles.

METHODS

Eighteen adult males with metabolic syndrome (defined according to IDF 2009) and Body Mass Index (BMI) between 25 and 35 kg/m² were subjected to a balanced hypocaloric diet for 6 months to reach at least a 5% body weight loss.

RESULTS

After weight loss, a significant improvement in BMI, waist circumference, insulin, fasting blood glucose and HOMA-IR (homeostasis model assessment of insulin resistance) was observed. The analysis of LDL (low-density lipoprotein cholesterol) and HDL (high-density lipoprotein cholesterol) lipoproteins showed a change in their composition with a massive transfer of triacylglycerols from HDL to LDL. This was associated with a significant reduction in peripheral pro-inflammatory cytokines such as IL-6, TNF-α, IL-8 and MIP-1β, leading to an overall decreased inflammatory score. An interesting positive correlation was also observed among peripheral cytokines levels after diet and peripheral levels of CETP (cholesteryl ester transfer protein), an enzyme with a key role in lipid change.

CONCLUSION

Weight loss through caloric restriction is associated with an improvement in peripheral lipid and cytokine profiles that may play a major role in improving cardiovascular risk.

Endocrine and metabolic assessment in adults with Langerhans cell histiocytosis

CONTEXT

Diabetes insipidus (DI) is one of most common complications of Langerhans cell histiocytosis (LCH) but prevalence of anterior pituitary deficiencies and metabolic alterations have not been clearly defined yet.

OBJECTIVES

Evaluate prevalence of endocrine and metabolic manifestations in a cohort of patients affected by Pulmonary LCH.

METHODS

Observational cross-sectional study on 18 adults (7 M/11 F, 42±12years) studied for complete basal and dynamic endocrine lab tests and glucose metabolism.

RESULTS

Hypothalamic-pituitary endocrine alterations were found in 9 patients: 9 had DI, 5 Growth Hormone Deficiency (GHD), 5 central hypogonadism, 3 central hypothyroidism and 1 central hypoadrenalism. Hyperprolactinemia and hypothalamic syndrome were found in 2 patients each. All these central endocrine alterations were always associated to DI. Five of the 10 MRI performed showed abnormalities. Prevalence of obesity and glucose alterations (either DM or IFG/IGT) were respectively 39% and 33%, higher than expected basing on epidemiological data on general Italian population. Multi-system-LCH without risk-organ involvement (LCH MS-RO^-) seems to have slightly higher prevalence of insulin resistance, glucose alterations and metabolic syndrome than LCH with isolated lung involvement (LCH SS lung⁺). A papillary BRAFV600E positive thyroid carcinoma was diagnosed in one patient.

CONCLUSIONS

The presence of anterior pituitary deficiencies should be systematically sought in all LCH patients with DI both at diagnosis and during the follow-up by basal and dynamic hormonal assessment. Patients with pulmonary LCH, particularly those with MS disease, have a worse metabolic profile than general population. Occurrence of papillary thyroid carcinoma has been reported.

Prevalence of GH deficiency in cured acromegalic patients: impact of different previous treatments

OBJECTIVE

Radiotherapy (RT) for pituitary adenomas, including GH-secreting ones, frequently leads to GH deficiency (GHD). Data on the effects of surgery alone (S) on dynamic GH secretion are limited. The aim of the study was to investigate the occurrence of GHD in acromegalic patients treated with different therapeutic options.

DESIGN AND METHODS

Fifty-six patients in remission from acromegaly, (33 F & 23 M, age: 54+/-13 years, body mass index (BMI): 28.4+/-4.1 kg/m(2), 21 with adequately substituted pituitary deficiencies) treated by S alone (n=33, group 1) or followed by RT (n=23, group 2), were investigated for GHD by GHRH plus arginine testing, using BMI-adjusted cut-offs. Several metabolic and cardiovascular parameters (waist circumference, body fat percentage, blood pressure, fasting and post-oral glucose tolerance test glucose, HbA1c, insulin resistance and lipid profile) were evaluated in all the patients and 28 control subjects with known diagnosis of GHD.

RESULTS

Serum GH peak after challenge was 8.0+/-9.7 microg/l, without any correlation with post-glucose GH nadir and IGF-1 levels. The GH response indicated severe GHD in 34 patients (61%) and partial GHD in 15 patients (27%). IGF-1 were below the normal range in 14 patients (25%). The frequency of GHD was similar in the two treatment groups (54% in group 1 and 70% in group 2). No significant differences in metabolic parameters were observed between acromegalic patients and controls with GHD.

CONCLUSIONS

Severe GHD may occur in about 60% of patients treated for acromegaly, even when cured after S alone. Thus, a stimulation test (i.e. GHRH plus arginine) is recommended in all cured acromegalic patients, independently from previous treatment.

Detection of small bowel tumors by videocapsule endoscopy in patients with acromegaly

The prevalence of colon polyposis andmalignancies is increased in acromegalic patients as compared to the general population. An epidemiological study suggests a high prevalence also of small bowel (SB) tumors that nowadays may be detected by videocapsule endoscopy (VCE). The aim of the study was to assess the prevalence of SB neoplasms using VCE in acromegalic patients in comparison to control subjects and to correlate it with cancer risk factors and acromegaly-related parameters. Eighteen acromegalic patients (6 males and 12 females, age+/-SD: 54+/-10 yr), 5 cured after surgery (followed by radiotherapy in 3 cases) and 13 on pharmacological treatment were enrolled, and 36 sex- and age-matched non-acromegalic subjects served as a control group. Cancer risk factors, duration of acromegaly, GH and IGF-I levels, IGF binding protein 3 and IGF-II concentrations, metabolic parameters, tumor markers, colonic lesions by total colonoscopy, and SB lesions by VCE were investigated. VCE images suggestive of SB lesions were detected in 5/36 controls [14%, 4 described as gastrointestinal stromal nodular tumors (GIST), and 1 as polyp] and in 5/18 acromegalic patients [28%, 2 GIST and 3 polyps]. In acromegaly, the calculated relative risk for all SB lesions was 1.69 [95%confidence interval (CI): 0.78-3.65], while the relative risk for SB polyps was 2.50 (95% CI: 1.23-5.07). The effective duration of active disease was longer in patients with positive than in those with negative VCE (112+/-89 vs 49+/-40 months, p=0.06). In conclusion, these preliminary results suggest that acromegalic patients might have a high risk of SB polyp development. VCE might be a useful adjunctive diagnostic tool in acromegaly.