Creatinine values during a competitive season in elite athletes involved in different sport disciplines

AIM

The authors aimed at studying creatinine concentrations in elite male athletes of rugby, alpine ski and cyclism, characterized from different Body Mass Index (BMI) to evaluate modifications during the competitions season.

METHODS

Creatinine was measured by Jaffe method in 44 top-level athletes (18 rugbyists, 13 skiers, and 13 cyclists) before the start of training and competitions and during the competitions season, three times for rugbyists and skiers, and two times for cyclists.

RESULTS

Creatinine concentrations were related to body mass and were significantly different among the groups of athletes of the three sports. Analysis of variance showed significant differences among groups of athletes practising different sports (P<0.0001). The analysis for repeated measures demonstrated significant differences for rugby (P<0.005) and ski (P<0.02), but not for cycling (P=0.25).

CONCLUSION

The interpretation of the creatinine concentrations in athletes should take in account the kind of sport practised, the BMI, and also the possible variations during the season. The reference intervals used for general population can not be used for athletes.

Relationship between soluble CD40 ligand and gamma-glutamyltransferase concentrations in non-drinking, young Type 1 diabetic individuals

AIMS

To assess the association between circulating levels of soluble CD40 ligand (sCD40L), an emerging cardiovascular risk factor, and gamma-glutamyltransferase (GGT) activity concentrations in Type 1 diabetic subjects.

METHODS

Plasma concentrations of sCD40L and GGT activity, a marker of liver dysfunction, were measured in 54 non-smoking, non-drinking, young Type 1 diabetic patients, who were free of diagnosed cardiovascular disease.

RESULTS

When participants were grouped according to tertiles of GGT, plasma sCD40L concentrations steadily increased across GGT tertiles (P = 0.007 for trend). Similarly, plasma sCD40L concentrations were positively correlated with plasma GGT levels in the whole group of participants (r = 0.532; P < 0.0001). In multivariate linear regression analysis, plasma GGT activity levels were positively associated with sCD40L (standardized beta coefficient = 0.342; P = 0.027) independently of age, gender, diabetes duration, glycated haemoglobin, total cholesterol and systolic blood pressure. Further adjustment for the presence of diabetic retinopathy and microalbuminuria did not appreciably attenuate this association.

CONCLUSIONS

Our findings suggest that there is a strong, graded, relationship between plasma GGT activity and sCD40L concentrations in non-smoking, non-drinking, young Type 1 diabetic individuals. This association appears to be independent of numerous confounding factors. Further studies are required to confirm the reproducibility of these results.

The Pro12Ala polymorphism of the PPARG gene is not associated with the metabolic syndrome in an urban population of middle-aged Swedish individuals

BACKGROUND

To determine if the common Pro12Ala polymorphism (rs1801282) of the peroxisome proliferator-activated receptor (PPARG) gene is associated with the metabolic syndrome (MetS) or with its individual components in middle-aged Swedish individuals.

METHODS

MetS was defined according to the National Cholesterol Education Program/Adult Panel III (NCEP/ATP III), the International Diabetes Federation (IDF) and the European Group for the Study of Insulin Resistance (EGIR) criteria in a population-based sample of nearly 5000 subjects participating in the Malmö Diet and Cancer-cardiovascular arm.

RESULTS

Of the subjects included in the analysis, 21.8, 29.4 and 20.4% had MetS according to the NCEP/ATP III, IDF and EGIR (only in subjects without diabetes) definitions, respectively. The Pro12Ala was not associated with MetS or with its individual components. These results were similar when patients with diabetes were excluded. Hypertensive and obese ala-carriers had lower fasting glucose and hypertensive ala-carriers also had lower level triglycerides (P < 0.05).

CONCLUSIONS

Our data do not support a major role for the Pro12Ala variant of the PPARG gene in MetS and its individual components. The modest difference in triglyceride and glucose levels, restricted to hypertensive and obese subjects in our cohort, suggests that the polymorphism has a minor effect on glucose and lipid metabolism, particularly in individuals at risk for gluco-metabolic disturbances.

Clinical, laboratory and therapeutic aspects of platelet-type von Willebrand disease

Platelet-type von Willebrand disease (PT-VWD), or pseudo-VWD, is a rare inherited platelet disorder characterized by an increased affinity of the platelet membrane glycoprotein Ibalpha receptor for normal von Willebrand factor leading to characteristic platelet hyperaggregability. As PT-VWD shares most of the clinical and laboratory features of subtype 2B VWD, the differential diagnosis between these two inherited bleeding disorders requires either platelet-mixing or molecular genetic studies. In this review, the main clinical, laboratory and therapeutic characteristics of PT-VWD are concisely reported.

Non-alcoholic fatty liver disease is independently associated with an increased prevalence of chronic kidney disease and proliferative/laser-treated retinopathy in type 2 diabetic patients

AIMS/HYPOTHESIS

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease in type 2 diabetes. Currently, there is a lack of information on associations between NAFLD and microvascular complications of diabetes. We assessed the associations between NAFLD and both chronic kidney disease (CKD) and retinopathy in a large cohort of type 2 diabetic individuals using a cross-sectional design.

METHODS

Prevalence rates of retinopathy (by ophthalmoscopy) and CKD (defined as overt proteinuria and/or estimated GFR <or= 60 ml min(-1) 1.73 m(-2)) were assessed in 2,103 type 2 diabetic individuals who were free of diagnosed cardiovascular disease and viral hepatitis. NAFLD was ascertained by patient history, blood sampling and liver ultrasound.

RESULTS

NAFLD patients had higher (p<0.001) age- and sex-adjusted prevalence rates of both non-proliferative (39 vs 34%) and proliferative/laser-treated retinopathy (11 vs 5%), and CKD (15 vs 9%) than counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with increased rates of CKD (odds ratio 1.87; 95% CI 1.3-4.1, p=0.020) and proliferative/laser-treated retinopathy (odds ratio 1.75; 1.1-3.7, p=0.031) independently of age, sex, BMI, waist circumference, hypertension, diabetes duration, HbA(1c), lipids, smoking status and medications use.

CONCLUSIONS/INTERPRETATION

Our findings suggest that NAFLD is associated with an increased prevalence of CKD and proliferative/laser-treated retinopathy in type 2 diabetic individuals independently of numerous baseline confounding factors. Further studies are required to confirm the reproducibility of these results and to evaluate whether NAFLD contributes to the development or progression of CKD and retinopathy.

Glycaemic Control in Athletes

Physical activity is essential for weight control, for limiting onset and complications of chronic disorders and for preventing impaired insulin sensitivity. Little is known about the glycaemic adaptations of physically active subjects, especially elite and professional athletes. Thus, we evaluated the glycaemic control in elite and professional cyclists by assessing fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c). The study population consisted of 47 male professional road cyclists, 72 male elite road cyclists and 58 male sedentary blood donors. A significant difference was observed for FPG between sedentary controls (96 +/- 8 mg/dL) and either elite (91 +/- 8 mg/dL; p < 0.001) or professional cyclists (89 +/- 8 mg/dl; p < 0.001). Athletes showed a consistent trend towards higher HbA1c values, reaching statistical significance between sedentary individuals and professional cyclists (5.2 +/- 0.3% versus 5.4 +/- 0.2%; p = 0.017). In multiple linear regression analysis, the intensity of physical exercise is inversely correlated with FPG (r = - 0.320; p < 0.001) and directly correlated with HbA1c (r = 0.190; p = 0.006). These results demonstrate a significant association between intensity of the training regimen and both FPG and HbA1c, highlighting the need for establishing the appropriate critical difference for the measurement of FPG and HbA1c according to the training and exercise workload.

Diabetic retinopathy is associated with an increased incidence of cardiovascular events in Type 2 diabetic patients

AIMS

We investigated the association of diabetic retinopathy with the risk of incident cardiovascular disease (CVD) events in a large cohort of Type 2 diabetic adults.

METHODS

Our study cohort comprised 2103 Type 2 diabetic outpatients who were free of diagnosed CVD at baseline. Retinal findings were classified based on fundoscopy (by a single ophthalmologist) to categories of no retinopathy, non-proliferative retinopathy and proliferative/laser-treated retinopathy. Outcomes measures were incident CVD events (i.e. non-fatal myocardial infarction, non-fatal ischaemic stroke, coronary revascularization procedures or cardiovascular death).

RESULTS

During approximately 7 years of follow-up, 406 participants subsequently developed incident CVD events, whereas 1697 participants remained free of diagnosed CVD. After adjustment for age, body mass index, waist circumference, smoking, lipids, glycated haemoglobin, diabetes duration and medications use, patients with non-proliferative or proliferative/laser-treated retinopathy had a greater risk (P < 0.001 for all) of incident CVD events than those without retinopathy [hazard ratio 1.61 (95% confidence interval 1.2-2.6) and 3.75 (2.0-7.4) for men, and 1.67 (1.3-2.8) and 3.81 (2.2-7.3) for women, respectively]. After additional adjustment for hypertension and advanced nephropathy (defined as overt proteinuria and/or estimated glomerular filtration rate < or = 60 ml/min/1.73 m(2)), the risk of incident CVD remained markedly increased in those with proliferative/laser-treated retinopathy [hazard ratio 2.08 (1.02-3.7) for men and 2.41 (1.05-3.9) for women], but not in those with non-proliferative retinopathy.

CONCLUSIONS

Diabetic retinopathy (especially in its more advanced stages) is associated with an increased CVD incidence independent of other known cardiovascular risk factors.

Subjects heterozygous for genetic loss of function of the thiazide-sensitive cotransporter have reduced blood pressure

Gitelmańs syndrome (GS) is an inherited recessive disorder caused by homozygous or compound heterozygous loss of function mutations of the NaCl cotransporter (NCCT) gene encoding the kidney-expressed NCCT, the pharmacological target of thiazide diuretics. An observational study estimated the prevalence of GS to 19/1,000,000, in Sweden, suggesting that approximately 1% of the population carries one mutant NCCT allele. As the phenotype of GS patients, who always carry two mutant alleles, is indistinguishable from that seen in patients treated with high-dose thiazide diuretics, we aimed at investigating whether subjects carrying one mutated NCCT allele have a phenotype resembling that of treatment with low-dose thiazide diuretics. We screened first-degree relatives of 18 of our patients with an established clinical end genetic diagnosis of GS for NCCT loss of function mutations and identified 35 healthy subjects carrying one mutant allele (GS-heterozygotes). Each GS-heterozygote was assigned a healthy control subject matched for age, BMI and sex. GS-heterozygotes had markedly lower blood pressure (systolic 103.3 +/- 16.4 versus 123.2 +/- 19.4 mmHg; diastolic 62.5 +/- 10.5 versus 73.1 +/- 9.4 mmHg; P < 0.001) than controls. There was no significant difference between the groups either in plasma concentration or urinary excretion rate of electrolytes, however, GS-heterozygotes had higher fasting plasma glucose concentration. Similar to patients being treated with low-dose thiazide diuretics, GS-heterozygotes have markedly lower blood pressure and slightly higher fasting plasma glucose compared with control subjects. Our findings suggest that GS-heterozygotes, the prevalence of which can be estimated to 1%, are partially protected from hypertension through partial genetic loss of function of the NCCT. However, as our study had a case-control design, it is important to underline that any potential effects on population blood pressure and risk of future cardiovascular disease need to be examined in prospective and population-based studies.

Impact of different inhibitor reactivities with commercial factor VIII concentrates on thrombin generation

In order to describe the haemostatic role of a variation in inhibitor reactivity with different factor VIII (FVIII) concentrates, we have compared inhibitor titres against a panel of FVIII concentrates and correlated titre with the capacity to inhibit thrombin generation. Three plasma-derived concentrates were tested in vitro in mixing experiments with inhibitor plasmas from 11 patients with severe haemophilia A: Fanhdi, which contains von Willebrand factor (VWF) with a final ratio of approximately 1:1 (VWF IU per IU FVIII:C); Haemate-P with a ratio of 2.5:1 and Hemofil-M containing only trace amounts of VWF. In addition, the recombinant FVIII concentrate Kogenate Bayer containing no VWF was included. Inhibitor titres and the capacity to generate thrombin were measured. A statistically significant difference in measured titres was found with the highest titres recorded against Hemofil-M. The inhibitor titres needed to inhibit 50% maximum thrombin generation were the lowest for Kogenate Bayer and the highest and similar for Fanhdi and Haemate-P with intermediate titres needed for inhibition of Hemofil-M. In this study, the thrombin generation assay provides additional indications for the role of VWF in the treatment of patients with inhibitors. The VWF-containing concentrates Fanhdi and Haemate-P, added to FVIII-deficient plasma with the presence of inhibitor, generate more thrombin than do the purified concentrates Hemofil-M and Kogenate Bayer.

Changes in technical regulations and drivers' safety in top-class motor sports

Motor racing is a dangerous sport and an inherently risky activity. The organisers of top-class motor sports championships, Formula One and MotoGP, have agreed on a set of regulations to reduce speed and improve safety over the last 10 years. These changes include limitations in weight, fuel and engine capacity. Nevertheless, there is evidence that most of the restrictions that have been introduced over the past 10 years have failed slow down vehicles, since the lap times have decreased almost linearly from 1995 to 2006 and drivers continue to die or to sustain serious injuries that keep them away from competition. Therefore, new and efficient measures should be adopted, such as lowering the cornering speed, having heavier and safer vehicles, having barriers surrounding the track to protect both spectators and competitors better, and having innovative clothing and protective devices to defend key anatomical structures while minimising the hindrance to the rider.

Increased D-dimer value and occult cancer in the absence of detectable thrombosis

Fibrin formation and removal occurs continuously during the development of malignancy. Accordingly, hemostatic disorders in cancer patients are a rather frequent observation and range from asymptomatic laboratory changes to massive thromboembolism or haemorrhage. We document the case of an asymptomatic women, who was enrolled as a healthy control in a study and showed up with a substantially increased D- dimer value. After ruling out the most probable sources of D-dimer elevation, such as thrombosis, inflammation and trauma, she underwent laboratory and radiological investigations for malignancy, which were consistent with a colorectal metastatic adenocarcinoma. This case allow us to hypothesize that screening for occult malignancy in the presence of apparently inexplicable elevated D-dimer values may be taken into consideration.