Response to Comment on Sprouse et al. SLC30A8 nonsynonymous variant is associated with recovery following exercise and skeletal muscle size and strength. Diabetes 2014;63:363-368

Half-Unit Insulin Pens: Disease Management in Patients With Diabetes Who Are Sensitive to Insulin

BACKGROUND

Insulin pens represent a significant technological advancement in diabetes management. While the vast majority have been designed with 1U-dosing increments, improved accuracy and precision facilitated by half-unit increments may be particularly significant in specific patients who are sensitive to insulin. These include patients with low insulin requirements and in those requiring more precise dose adjustments, such as the pediatric patient population. This review summarized functional characteristics of insulin half-unit pens (HUPs) and their effect on user experience.

METHODS

The literature search was restricted to articles published in English between January 1, 2000, and January 1, 2015. A total of 17 publications met the set criteria and were included in the review.

RESULTS

Overall, studies outlined characteristics for 4 insulin HUPs. Based on their functionality, the pens were generally similar and all met the ISO 11608-1 criteria for accuracy. However, some had specific advantageous features in terms of size, weight, design, dialing torque, and injection force. Although limited, the currently available user preference studies in children and adolescents with diabetes and their carers suggest that the selection of an HUP is likely to be influenced by a combination of factors such as these, in addition to the prescribed insulin and dosing regimen.

CONCLUSIONS

Insulin HUPs are likely to be a key diabetes management tool for patients who are sensitive to insulin; specific pen features may further advance diabetes management in these populations.

Elite athletes' genetic predisposition for altered risk of complex metabolic traits

BACKGROUND

Genetic variants may predispose humans to elevated risk of common metabolic morbidities such as obesity and Type 2 Diabetes (T2D). Some of these variants have also been shown to influence elite athletic performance and the response to exercise training. We compared the genotype distribution of five genetic Single Nucleotide Polymorphisms (SNPs) known to be associated with obesity and obesity co-morbidities (IGF2BP2 rs4402960, LPL rs320, LPL rs328, KCJN rs5219, and MTHFR rs1801133) between athletes (all male, n = 461; endurance athletes n = 254, sprint/power athletes n = 207), and controls (all male, n = 544) in Polish and Russian samples. We also examined the association between these SNPs and the athletes' competition level ('elite' and 'national' level). Genotypes were analysed by Single-Base Extension and Real-Time PCR. Multinomial logistic regression analyses were conducted to assess the association between genotypes and athletic status/competition level.

RESULTS

IGF2BP2 rs4402960 and LPL rs320 were significantly associated with athletic status; sprint/power athletes were twice more likely to have the IGF2BP2 rs4402960 risk (T) allele compared to endurance athletes (OR = 2.11, 95% CI = 1.03-4.30, P <0.041), and non-athletic controls were significantly less likely to have the T allele compared to sprint/power athletes (OR = 0.62, 95% CI =0.43-0.89, P <0.0009). The control group was significantly more likely to have the LPL rs320 risk (G) allele compared to endurance athletes (OR = 1.26, 95% CI = 1.05-1.52, P <0.013). Hence, endurance athletes were the "protected" group being significantly (p < 0.05) less likely to have the risk allele compared to sprint/power athletes (IGF2BP2 rs4402960) and significantly (p < 0.05) less likely to have the risk allele compared to controls (LPL rs320). The other 3 SNPs did not show significant differences between the study groups.

CONCLUSIONS

Male endurance athletes are less likely to have the metabolic risk alleles of IGF2BP2 rs4402960 and LPL rs320, compared to sprint/power athletes and controls, respectively. These results suggest that some SNPs across the human genome have a dual effect and may predispose endurance athletes to reduced risk of developing metabolic morbidities, whereas sprint/power athletes might be predisposed to elevated risk.