Dipeptidyl peptidase-4 inhibitors and bone metabolism: is vitamin D the link?

AIMS: Dipeptidyl peptidase-4 inhibitors (DPP4-Is) represent a promising class of agents for type 2 diabetes treatment. Experimental models and clinical studies have reported positive effects of DPP4-Is on bone; however, how DPP4-Is positively impact bone homeostasis in humans remains an unanswered question. Aim of this study investigated the relationship between treatment with DPP4-Is and vitamin D balance in patients with type 2 diabetes. METHODS: This is a cross-sectional study. A total of 295 consecutive individuals with type 2 diabetes referring to our diabetes outpatient clinics were enrolled; among them, 53 % were in treatment with DPP4-Is. Metabolic profile and routine biochemistry were assessed by standard methods; serum 25(OH) vitamin D levels [25(OH)D] were measured by colorimetric method (LAISON, DiaSorin). RESULTS: DPP4-Is-treated participants had significantly higher serum 25(OH)D levels then those undertaking other antidiabetic therapies (18.4 ± 10.7 vs. 14.9 ± 8.6 ng/ml, p = 0.004); this association persisted after adjusting for all major confounders. Increased 25(OH)D concentrations also correlated with the duration of DPP4-Is treatment and with a stronger DPP4 inhibitory activity. CONCLUSIONS: DPP4-Is treatment is associated with improved vitamin D balance in people with type 2 diabetes; our findings suggest that vitamin D may underlie the link between DPP4-Is and bone metabolism.

Personality variables and compliance with insulin therapy in Type 2 diabetic subjects.

Forty-five diabetic patients were studied to evaluate adaptation and coping strategies. The authors have also analysed personality traits mainly to study different behaviour in compliance conduct. The results revealed an important psychological dimension made up of difficulties in accepting insulin immediately, in fear of addiction and doubts about the therapy. On the basis of these results the sample was then divided into two subgroups, which were then tested and compared with the Adjective Check List. The subgroup that showed more fear, insecurity and initial resistance towards insulin therapy appeared to be more rigid and seemingly conforming. These people also revealed personality aspects compatible with the presence of passive-aggressive and avoidant traits.

Diabetes mellitus: lessons from patient education.

The education of diabetic patients, proposed as an essential therapeutic tool since the early 1920s and accepted as such by official medicine only in the 1970s, has generated great enthusiasm over the last decade, with increasing concern for greater effectiveness by improved motivation of both patients and doctors. Structured education depends on the precise definition of agreed, short-term objectives, whose attainment shall be verified. Educational objectives may be set at different levels: knowledge of the disease, skills required for treatment, capacity to integrate therapy in everyday life,... The most relevant objectives however are the therapeutic goals of each individual patient, i.e. most often, prevention of acute complications, near-normoglycemia to prevent late complications and foot care to prevent disabling consequences of the latter. This can only be attained through a global approach to the patient, at once medical, educational and psychological. Medical science has definitively confirmed the importance of near- normoglycemia and proposes more effective insulin regimens and new recommendations for diet and exercise. Education demands a lot from health care providers: specific training, teaching skills, good communication, supportive attitude, readiness to listen and to negotiate. Patients' motivation to learn and adhere to treatment is also greatly influenced by individual factors, both psychological and environmental, that need to be taken into account.

The effect of muesli or cornflakes at breakfast on carbohydrate metabolism in type 2 diabetic patients.

Fourteen overweight insulin-treated type 2 diabetic patients ate a breakfast, consisting of either muesli (slow release starch: SRS) or cornflakes (fast release starch: FRS), in either case with milk (46 g carbohydrate), during two consecutive randomized crossover periods of two weeks. The rest of the diet remained unchanged. At the end of each period the patients underwent a glucose tolerance test after an overnight fast without their usual evening insulin injection. Both mean plasma glucose responses curves were identical after the two dietary periods, but plasma insulin was significantly lower at zero (-17%, P less than 0.05) and 2 h (-21%, P less than 0.05) at the end of the muesli (SRS) period as compared to the cornflakes (FRS) period. The mean day-long plasma glucose level (four measurements) at the end of the muesli period was 21% (P = 0.023) lower than after the cornflakes period. These results show that switching, at breakfast only, from standard cereals to slow release starch cereals improves the carbohydrate metabolism of diabetic patients. In addition, the fact that diabetic patients could reduce their insulin requirement (P less than 0.05) with concomitant reduction of their daily blood glucose level implies that sensitivity to insulin was improved by slow release starct foods consumed at breakfast.

The Thermocross: a simple tool for rapid assessment of thermal sensation thresholds.

We have developed the Thermocross, a simple device for rapid assessment of thermal sensitivity, tested it on healthy subjects and diabetic patients and evaluated its use in identifying patients whose sensation loss may expose them to the risk of neuropathic foot injury. Thermal discrimination deteriorated with age (P less than 0.001) in healthy subjects, but all the controls could detect a temperature difference less than or equal to 10 degrees C. In diabetic patients, the deficit in thermal sensation detected by the Thermocross paralleled the decline of nerve conduction. Thermocross thermal sensation was impaired in 87% of 38 ulcerated feet of 26 diabetic patients. We conclude that the Thermocross is a suitable tool for screening for sensation loss and that diabetic patients with impaired thermal sensation are vulnerable to ulceration. The Thermocross could also serve a useful educational purpose, the implications of reduced thermal sensation probably being more meaningful to patients and health care personnel than those of a reduction in the traditionally tested vibration sensation.

The tuning fork revisited.

The performance of the Rydel-Seiffer graduated tuning fork was examined in healthy subjects and in various groups of diabetic patients in order to evaluate its efficacy for identifying patients whose loss of vibration sensation may expose them to the risk of foot injury. Vibration perception score measured with the tuning fork declined with age (p less than 0.001) in the control subjects. It correlated well (r = -0.90, p less than 0.001) with the thresholds obtained with an electromagnetic instrument (Vibrameter) in diabetic patients, in whom vibration perception score was impaired compared with control subjects (4.0 +/- 1.8 (+/- SD) vs 5.4 +/- 1.4, p less than 0.001). Age-related Rydel-Seiffer tuning fork vibration sensation was impaired in 79% of 38 ulcerated feet of 26 patients. The tuning fork score was less than or equal to 4.0 in 95% of the ulcerated feet. We conclude that the Rydel-Seiffer graduated tuning fork is a suitable tool for screening for sensation loss and that diabetic patients with a tuning-fork score of less than or equal to 4.0 are vulnerable to ulceration.