Fine needle aspiration coupled with real-time PCR: a painless methodology to study adaptive functional changes in skeletal muscle.

BACKGROUND AND AIM: In this study we developed a new methodology for obtaining human skeletal muscle samples to evaluate gene expression. This approach is based on a fine needle aspiration technique, which allows us to extract a small tissue sample in a significantly less invasive manner than with classic biopsy. METHODS AND RESULTS: Multiplex tandem RT-PCR was used to determine the mRNA levels of genes involved in ATP production and mitochondrial biogenesis in muscle tissue. Samples of vastus lateralis muscle were obtained from 21 healthy subjects with different fitness levels. The principal findings in our study show a strong correlation between PGC-1alpha and COX5B (p<0.001) and between PGC-1alpha and MT-CO2 (p=0.017) expression. Furthermore, a significant positive correlation between mtDNA content and the percentage of MHCI present in the aspired samples were found (p=0.028). These data are in agreement with current knowledge on skeletal muscle physiology and show the reliability of the proposed method. CONCLUSION: This painless methodology can be used to investigate, in vivo, human muscle RNA and DNA adaptations in response to either physiological and/or pharmacological stimuli. This method has major clinical relevance, such as its application in clarifying the mechanisms underling metabolic and systemic disorders.

Exercise and diabetes.

Physical activity activates has acute and chronic effects on glucose, lipid and protein metabolism. In type 1 diabetic subjects, the lack of the physiological inhibition of insulin secretion during exercise results in a potential risk of hypoglycemia. On the other hand, exercise-induced activation of counterregulatory hormones might trigger an acute metabolic derangement in severe insulin-deficient subjects. Thus, diabetic patients, before starting exercise sessions, must be carefully educated about the consequences of physical activity on their blood glucose and the appropriate modifications of diet and insulin therapy. Long-term effects of regular exercise are particularly advantageous for type 2 diabetic patients. Regular aerobic exercise reduces of visceral fat mass and body weight without decreasing lean body mass, ameliorates insulin sensitivity, glucose and blood pressure control, lipid profile and reduces the cardiovascular risk. For these reasons, regular aerobic physical activity must be considered an essential component of the cure of type 2 diabetes mellitus. In this regard, individual behavioral strategies have been documented to be effective in motivating sedentary type 2 diabetic subjects to the adoption and the maintenance of regular physical activity.

Make your diabetic patients walk: long-term impact of different amounts of physical activity on type 2 diabetes.

OBJECTIVE: To establish the impact of different amounts of increased energy expenditure on type 2 diabetes care. RESEARCH DESIGN AND METHODS: Post hoc analysis of long-term effects of different amounts of increased energy expenditure (metabolic equivalents [METS] per hour per week) through voluntary aerobic physical activity was performed in 179 type 2 diabetic subjects (age 62 +/- 1 years [mean +/- SE]) randomized to a physical activity counseling intervention. Subjects were followed for 2 years and divided into six groups based on their increments in METs per hour per week: group 0 (no activity, n = 28), group 1-10 (6.8 +/- 0.3, n = 27), group 11-20 (17.1 +/- 0.4, n = 31), group 21-30 (27.0 +/- 0.5, n = 27), group 31-40 (37.5 +/- 0.5, n = 32), and group >40 (58.3 +/- 1.8, n = 34). RESULTS: At baseline, the six groups did not differ for energy expenditure, age, sex, diabetes duration, and all parameters measured. After 2 years, in group 0 and in group 1-10, no parameter changed; in groups 11-20, 21-30, 31-40, and >40, HbA(1c), blood pressure, total serum cholesterol, triglycerides, and estimated percent of 10-year coronary heart disease risk improved (P < 0.05). In group 21-30, 31-40, and >40, body weight, waist circumference, heart rate, fasting plasma glucose, serum LDL and HDL cholesterol also improved (P < 0.05). METs per hour per week correlated positively with changes of HDL cholesterol and negatively with those of other parameters (P < 0.001). After 2 years, per capita yearly costs of medications increased (P = 0.008) by USD393 in group 0, did not significantly change in group 1-10 (USD 206, P = 0.09), and decreased in group 11-20 (USD -196, P = 0.01), group 21-30 (USD -593, P = 0.009), group 31-40 (USD -660, P = 0.003), and group >40 (USD -579, P = 0.001). CONCLUSIONS: Energy expenditure >10 METs . h(-1) . week(-1) obtained through aerobic leisure time physical activity is sufficient to achieve health and financial advantages, but full benefits are achieved with energy expenditure >20 METs . h(-1) . week(-1).