Determination of reference values for a novel ketoamine-specific fructosamine assay for assessment of diabetic glycemic control

Biochemical Changes Induced by the Administration of Cannabis sativa Seeds in Diabetic Wistar Rats

The present pilot study investigates the blood biochemical changes induced by hemp seeds in rats with diabetes. The composition of industrial hemp seeds, antioxidant activity, identification and quantification of phenols and fatty acids from hemp oil were determined. The Wistar adult rats used in the experiment were divided into three groups (n = 6) and kept under standard conditions. Group one, the control group (individuals without diabetes), and group two (diabetic individuals) received water and normal food ad libitum, while the third group, also including diabetic individuals, received specific food (hemp seeds) and water ad libitum. Subsequent blood biochemical parameters were determined. Hemp seeds had higher phenol (14 compounds), flavonoids and PUFA contents compared to other plants seeds. In addition, the antioxidant activity in Cannabis sativa was also increased. Moreover, the ratio between n-6 and n-3 was 4.41, ideal for different diseases. Additionally, all biochemical parameters showed significant changes following the treatment. It was shown that high doses of hemp seeds decreased diabetes-induced biochemical damage in rats most probably due to the high content of active compounds. In order to use these seeds in humans, it is essential to find out which hemp compounds are particularly responsible for these effects. Moreover, for the objective investigation of their effects, longer-term studies are needed.

Potential Clinical Error Arising From Use of HbA1c in Diabetes: Effects of the Glycation Gap

The glycation gap (GGap) and the similar hemoglobin glycation index (HGI) define consistent differences between glycated hemoglobin and actual glycemia derived from fructosamine or mean blood glucose, respectively. Such a disparity may be found in a substantial proportion of people with diabetes, being >1 U of glycated HbA1c% or 7.2 mmol/mol in almost 40% of estimations. In this review we define these indices and explain how they can be calculated and that they are not spurious, being consistent in individuals over time. We evaluate the evidence that GGap and HGI are associated with variation in risk of complications and mortality and demonstrate the potential for clinical error in the unquestioning use of HbA1c. We explore the underlying etiology of the variation of HbA1c from mean glucose in blood plasma, including the potential role of enzymatic deglycation of hemoglobin by fructosamine-3-kinase. We conclude that measurement of GGap and HGI are important to diabetes clinicians and their patients in individualization of therapy and the avoidance of harm arising from consequent inappropriate assessment of glycemia and use of therapies.

Low birth weight and elevated head-to-abdominal circumference ratio are associated with elevated fetal glycated serum protein concentrations

OBJECTIVE

To analyze the association between low birth weight, head-to-abdominal circumference ratio, and insulin resistance in early life.

METHOD AND RESULTS

Glycated serum proteins (GSPs) were quantified at delivery in 612 Chinese mother/child pairs serving as a surrogate of maternal and fetal glycemia. Differential ultrasound examination of the fetal's body (head circumference, biparietal diameter, pectoral diameter, abdominal circumference, and femur length) was done in average 1 week prior to delivery. Multivariable regression analysis considering gestational age at delivery, the child's sex, maternal BMI, maternal age at delivery, maternal body weight, and pregnancy-induced hypertension revealed that fetal GSP was inversely associated with birth weight (R² = 0.416; P < 0.001). Fetal GSP was furthermore positively associated with the head-to-abdominal circumference ratio, whereas the maternal GSP was negatively correlated with the offspring's head-to-abdominal circumference ratio (R² = 0.285; P = 0.010 and R² = 0.261; P = 0.020, respectively). The increased head-to-abdominal circumference ratio in newborns with higher fetal GSP is mainly due to a reduced abdominal circumference rather than reduced growth of the brain.

CONCLUSION

The disproportional intrauterine growth is in line with the concept of so-called brain sparing, a mechanism maintaining the intrauterine growth of the brain at the expense of trunk growth. Our data suggest that the low birth weight phenotype, linked to cardiovascular diseases like hypertension in later life, might be a phenotype of disproportional intrauterine growth retardation and early life insulin resistance.

Intermuscular adipose tissue rivals visceral adipose tissue in independent associations with cardiovascular risk

BACKGROUND

The metabolic implications of intermuscular adipose tissue (IMAT) are poorly understood compared to those of visceral adipose tissue (VAT) even though the absolute quantities of both depots are similar in many individuals.

OBJECTIVE

The aim was to determine the independent relationship between whole-body IMAT and cardiovascular risk factor parameters.

DESIGN

Whole body magnetic resonance imaging (MRI) was used to quantify total skeletal muscle (SM), total adipose tissue (TAT) of which IMAT, defined as the AT visible by MRI within the boundary of the muscle fascia, is a sub-component. Fasting serum measures (n=262) of glucose, total cholesterol (T-Chol), high-density lipoprotein cholesterol (HDL-Chol), triglycerides (TG), protein bound glucose (PBG, n=206) and insulin (n=119) were acquired in healthy African-American (AA, n=78) and Caucasian (Ca, n=109) women (body mass index (BMI) 26.5+/-5.7 kg/m(2); 44.4+/-16.4 years) and men (39 AA, 62 Ca; BMI 25.6+/-3.5 kg/m(2); 45.6+/-17.4 years). General linear models identified the independent effects of IMAT after covarying for SM, VAT, TAT, race, sex and two-way interactions.

RESULTS

Significant independent associations were observed for IMAT with glucose (P<0.001), PBG (P<0.001) and T-Chol (P<0.05). The association of IMAT with cholesterol differed by race in such a manner that for a unit increase in IMAT, T-Chol increased more rapidly in Ca compared to AA (P<0.05). TG, HDL-Chol and insulin had no independent association with IMAT.

CONCLUSION

The strong independent associations of IMAT with fasting glucose and PBG suggest that IMAT may be related to glucose metabolism; however, IMAT is also associated with T-Chol in Ca.

Treatment with insulin glargine does not suppress serum IGF-1

AIMS

A 6-8-fold higher insulin-like growth factor 1 (IGF-1) receptor binding affinity in vitro is reported for the insulin analogue glargine compared with human insulin. This study evaluates the in vivo significance by exploring the growth hormone (GH)-IGF-1 axis. Assuming a higher binding affinity of insulin glargine to pituitary IGF-1 receptors, serum IGF-1 concentrations should decrease via negative feedback.

METHODS

In a crossover study, insulin glargine or NPH insulin, respectively, were used in identical doses as basal insulins in treatment periods of 3 weeks.

RESULTS

Overall glycaemic control was not different between the treatment regimens. In contrast to the hypothesis, serum IGF-1 concentrations were higher during insulin glargine treatment compared with NPH insulin in patients with Type 1 diabetes (177 +/- 18 vs. 159 +/- 18 microg/l, P < 0.02, n = 17, age 28 +/- 2 years). The effect on IGF-1 was most pronounced in male patients with Type 1 diabetes (174 +/- 11 vs. 146 +/- 10 microg/l, P < 0.02, n = 10), but was not significant in patients with Type 2 diabetes (92 +/- 9 vs. 86 +/- 8 microg/l, NS, n = 25, age 66 +/- 2 years).

CONCLUSIONS

In contrast to our hypothesis, serum IGF-1 did not decrease, but rose during insulin glargine treatment, suggesting an absence of relevant IGF-1-like activity of glargine at the level of the pituitary. Improved plasma glucose at dawn during glargine treatment may intensify growth hormone surges and increase IGF-1 synthesis. Significant increases were seen in younger patients, compatible with the higher activity of the GH-IGF-1 axis in this age group.