Glycaemic variability affects ischaemia-induced angiogenesis in diabetic mice.

The aim of the present study was to investigate the role of GV (glycaemic variability) in diabetic vascular complications and to explore the molecular pathways modulated by glycaemic 'swings'. We developed a murine model. A total of 30 diabetic mice received once daily basal insulin administration plus two oral boluses of glucose solution (GV group, named 'V') and 30 diabetic mice received once daily basal insulin plus two oral boluses of saline solution (stable hyperglycaemia group, named 'S') for a period of 30 days. Glycaemia was measured eight times daily to detect GV. Finally, postischaemic vascularization, induced by hindlimb ischaemia 30 days after diabetes onset, was evaluated. We found that GV was significantly different between S and V groups, whereas no significant difference in the mean glycaemic values was detected. Laser Doppler perfusion imaging and histological analyses revealed that the ischaemia-induced angiogenesis was significantly impaired in V mice compared with S group, after ischaemic injury. In addition, immunostaining and Western blot analyses revealed that impaired angiogenic response in V mice occurred in association with reduced VEGF (vascular endothelial growth factor) production and decreased eNOS (endothelial nitric oxide synthase) and Akt (also called protein kinase B) phosphorylation. In conclusion, we describe a murine model of GV. GV causes an impairment of ischaemia-induced angiogenesis in diabetes, likely to be independent of changes in average blood glucose levels, and this impaired collateral vessel formation is associated with an alteration of the VEGF pathway.

Association between osteoprotegerin G1181C and T245G polymorphisms and diabetic charcot neuroarthropathy: a case-control study.

OBJECTIVE: Charcot neuroarthropathy is a disabling complication of diabetes. Although its pathogenesis remains unknown, we suppose that genetics may play a relevant role. RESEARCH DESIGN AND METHODS: We performed a case-control study with 59 subjects with diabetic Charcot neuroarthropathy (Ch group), 41 with diabetic neuropathy without Charcot neuroarthropathy (ND group), and 103 healthy control subjects (H group) to evaluate the impact of two single nucleotide polymorphisms (SNPs) of the osteoprotegerin gene (G1181C and T245G) on the risk of Charcot neuroarthropathy. RESULTS: Regarding the SNPs of G1181C, we found a significant linkage between the G allele and Charcot neuroarthropathy (Ch vs. ND, odds ratio [OR] 2.32 [95% CI 1.3-4.1], P = 0.006; Ch vs. H, 2.10 [1.3-3.3], P = 0.002; and ND vs. H, 0.90 [0.7-1.9], P = 0.452); similarly, we found a linkage with the G allele of T245G (Ch vs. ND, 6.25 [2.2-19.7], P < 0.001; Ch vs. H, 3.56 [1.9-6.7], P = 0.001; and ND vs. H, 0.54 [0.6-5.7], P = 0.304), supporting a protective role for the allele C and T, respectively. For this reason we investigated the frequency of the protective double homozygosis CC + TT (7% in Ch) that was significantly lower in Ch compared with H (0.18 [0.06-0.5], P = 0.002) and with ND (0.17 [0.05-0.58], P = 0.006), whereas there was no difference between H and ND (1.05 [0.43-2.0], P = 0.468). In a multivariate logistic backward regression model, only weight and the lack of CC and TT genotypes were independently associated with the presence of Charcot neuroarthropathy. CONCLUSIONS: This is the first study that shows an association between genetic regulation of bone remodeling and Charcot neuroarthropathy.

Estrogen-progestin therapy in women after stem cell transplant: our experience and literature review.

Women undergoing stem cell transplantation (SCT) are mostly young and have more than 90% probability of ovarian failure, which is often permanent. A woman's age, use of radiotherapy and alkylating chemotherapy, and the allogeneic type of transplant are associated with a higher rate of premature ovarian failure and worse residual ovarian function. Premature ovarian failure has serious systemic and psychological effects that may need treatment and should be managed by practitioners trained to treat this particular population of women. Ultrasonographic evidence of ovarian follicles is often associated with a future resumption of cycles, but there are no serum markers to predict the return of ovarian function in these patients. In our center, the rate of ovarian function recovery was 7% after allogeneic SCT and 25% after autologous SCT (P<0.05). There are no guidelines on how to manage premature ovarian failure induced by myeloablative treatments followed by SCT. Because of the likelihood of the need for long-lasting estrogen plus progestin therapy (EPT) and the increased risk of secondary neoplasia after SCT, the EPT should be as physiological as possible. In our experience, the cyclical sequential combination of estradiol (2 mg daily) plus dydrogesterone (10 mg for 14 d/mo) was associated with excellent compliance because of its simple administration and few adverse effects. Such a treatment led to a dramatic improvement in vasomotor, urogenital, and psychological symptoms related to estrogen deficiency. However, in the allogeneic transplantation setting, up to 25% of women may suffer from gynecological chronic graft-versus-host disease, which may become apparent as hematocolpometra after introduction of EPT. Thus, accurate pretreatment evaluation and frequent monitoring during treatment are required. Moreover, EPT absorption may be reduced in patients who received allotransplants and have gastrointestinal or skin chronic graft-versus-host disease.