Increased insulin sensitivity in individuals with neurofibromatosis type 1

Abstract

Objects To compare insulin resistance (IR) and metabolic aspects of patients with neurofibromatosis type 1 (NF1) and individuals without the disease. Subjects and methods Forty patients with NF1 were matched by sex, age, and body mass index (BMI) to 40 controls from the community. Blood samples were collected for biochemical assessment. Homeostasis model assessment adiponectin (HOMA-AD), Homeostasis model assessment insulin resistance (HOMA-IR), and adiponectin/leptin ratio (ALR) were used to identify IR. Results The median HOMA-IR values were similar between the groups. However, the HOMA-AD value was significantly lower and the ALR significantly higher in the NF1 group. Fasting blood glucose (FBG), leptin, and visfatin levels of patients with NF1 were significantly lower, although adiponectin levels were significantly higher than those in the controls. Fasting insulin and blood glucose levels 2 hours after administration of 75 g of dextrose, glycated hemoglobin, and resistin showed no significant differences between groups. The HOMA-AD correlated with BMI, FBG, blood glucose levels 2 hours after administration of 75 g of dextrose, fasting insulin, glycated hemoglobin, adiponectin, leptin, visfatin, ALR, and HOMA-IR. The ALR correlated with BMI leptin, visfatin, and adiponectin. Conclusions Lower levels of FBG, leptin, visfatin, and HOMA-AD, and higher adiponectin levels and ALR may be related to increased insulin sensitivity and lower occurrence of type 2 diabetes mellitus in patients with NF1.

Resting Energy Expenditure in Neurofibromatosis Type 1: Indirect Calorimetry versus Predictive Equations

“…The use of these equations can lead to inadequate energy consumption in this population, and long-term underfeeding can cause changes in body composition, such as reduced muscle mass and weight, and, consequently, metabolic and hormonal alterations 28,29 . NF1 patients usually have low weight, height, and lean body mass, as described in previous studies 7, 26,27,30 . Although some nutritional studies on NF1 have been carried out recently, little is known about the impact of diet and nutrition on the clinical characteristics of the disease 6,7,30 .…”

Neurofibromin is essential to maintain metabolic function and sustain life in the adult mouse

“…Similarly, there are also repeated studies reporting a lower occurrence of diabetes mellitus in NF1 patients (37)(38)(39). A recent study found that NF1 patients have increased insulin sensitivity, lower levels of fasting blood glucose, and higher adiponectin levels (40). A study also observed excessive intake of saturated fatty acids and lipids in NF1 patients (41).…”

Haploinsufficiency of theNF1gene is associated with protection against diabetes

“…[27][28][29][30][31][32] Lower fasting blood glucose concentrations have been reported in NF1 compared with control persons. [33][34][35] A reduced rate of gestational diabetes was observed in one cohort of patients with NF1 36 but not in another. 37 An analysis of insurance claims reported OR of 0.4 for diabetes among patients with NF1 in the USA.…”