Biomedical subjects

Carmen Castaneda

Publications and source records attributed to Carmen Castaneda.

7 recordsLinked to original sources

PubMed2006

Skeletal muscle sodium glucose co-transporters in older adults with type 2 diabetes undergoing resistance training.

We examined the expression of the sodium-dependent glucose co-transporter system (hSGLT3) in skeletal muscle of Hispanic older adults with type 2 diabetes. Subjects (65+/-8 yr) were randomized to resistance training (3x/wk, n=13) or standard of care (controls, n=5) for 16 weeks. Skeletal muscle hSGLT3 and GLUT4 mRNA transcript levels were determined by real time RT-PCR. hSGLT3 transcripts increased by a factor of ten following resistance training compared to control subjects (0.10, P=0.03). There were no differences in GLUT4 mRNA expression levels between groups. Protein expression levels of these transporters were confirmed by immunohistochemistry and Western blotting. hSGLT3 after resistance exercise was found not to be co-localized with the nicotinic acetylcholine receptor. The change in hSGLT3 transcript levels in the vastus lateralis muscle was positively correlated with glucose uptake, as measured by the change in muscle glycogen stores (r=0.53, P=0.02); and with exercise intensity, as measured by the change in muscle strength (r=0.73, P=0.001). Group assignment was be the only independent predictor of hSGLT3 transcript levels, explaining 68% of its variability (P=0.01). Our data show that hSGLT3, but not GLTU4, expression was enhanced in skeletal muscle after 16 weeks of resistance training. This finding suggests that hSGLT3, an insulin-independent glucose transporter, is activated with exercise and it may play a significant role in glycemic control with muscle contraction. The hSGLT3 exact mechanism is not well understood and requires further investigation. However its functional significance regarding a reduction of glucose toxicity and improvement of insulin resistance is the subject of ongoing research.

Journal Article↗

PubMed2005

Ethnic comparisons of sarcopenia and obesity in diabetes.

OBJECTIVE: To examine the association between obesity and low relative skeletal muscle mass (sarcopenia) with type 2 diabetes and poor glycemic control, and to determine whether these associations varied by ethnicity. DESIGN, SETTING, PARTICIPANTS: Data from the Third National Health and Nutrition Examination Survey (NHANES III) was used (5,727 adults, 40-74 years of age: 26% Mexican Americans, 25% non-Hispanic Blacks, and 49% non-Hispanic Whites). MAIN OUTCOME MEASURES: Sarcopenia was defined as a skeletal muscle [SM(kg)/ height(m2)] <1 standard deviation below the young adult mean. Obesity was defined as waist circumference >102 cm in men and >88 cm in women. RESULTS: The prevalence of diabetes was 40% higher in Mexican Americans than in non-Hispanic Blacks or Whites (P<.05). The lowest prevalence of obesity and sarcopenia were observed in Mexican Americans (except for obesity in women). Independent of ethnicity, subjects with a high waist circumference were more likely to have diabetes and poor glycemic control (P<.05). These associations were strongest in non-Hispanic Whites. Conversely, sarcopenia was not associated with diabetes or poor glycemic control in any ethnic group. CONCLUSIONS: Although the prevalence of type 2 diabetes was highest in Mexican Americans, non-Hispanic Whites exhibited the highest prevalence of obesity and sarcopenia. The role of genetically based, ethnic differences in body composition and diabetes risk needs to be taken into account when developing clinical guidelines such as the waist circumference cutpoints used in this study.

Adult↗

PubMed2004

Resistance training to reduce the malnutrition-inflammation complex syndrome of chronic kidney disease.

BACKGROUND: Systemic inflammation and protein-energy malnutrition may be associated with poor outcomes in kidney disease. METHODS: We studied 26 adults (age, 65 +/- 10 [SD] years) with chronic kidney disease, not on dialysis therapy. Subjects were randomly assigned to resistance training (n = 14) or a control group (n = 12) for 12 weeks, while counseled to consume a low-protein diet (protein, approximately 0.6 g/kg/d). We determined whether resistance training reduces levels of inflammatory mediators (serum C-reactive protein [CRP] and interleukin-6 [IL-6]), in addition to previously reported improvements in nutritional and functional status in this same subject population. RESULTS: Serum CRP levels were reduced in subjects undergoing resistance training (-1.7 mg/L) compared with controls (1.5 mg/L; P = 0.05). Similarly, IL-6 levels were reduced in the resistance-exercise group versus controls (-4.2 versus 2.3 pg/mL; P = 0.01). Resistance training lead to skeletal muscle hypertrophy, shown by increases in type I (24% +/- 31%) and type II (22% +/- 41%) muscle fiber cross-sectional areas, compared with control subjects (-14% +/- 34% and -13% +/- 18%, respectively; P < 0.05). Muscle strength also improved with resistance training (28% +/- 14%) compared with controls (-13% +/- 22%; P = 0.001). CONCLUSION: Resistance training reduced inflammation and improved nutritional status in individuals with moderate chronic kidney disease consuming a low-protein diet. These results need to be investigated further in larger cohorts of patients with varying stages of kidney disease to determine whether resistance training can improve disease outcomes long term.

Aged↗

PubMed2004

The effects of multidimensional home-based exercise on functional performance in elderly people.

BACKGROUND: This study tested the hypothesis that a home-based exercise program would improve functional performance in elderly people. METHODS: We conducted a 6-month, single-blinded, randomized controlled trial. 72 community dwelling men and women (aged >/=70 years) with self-reported and laboratory-based functional impairment were recruited for the study. Participants were randomly assigned to either a home-based progressive strength, balance, and general physical activity intervention or an attention-control group that received home-based nutrition education. Functional performance was measured in the laboratory using the Physical Performance Test (PPT) and the Established Populations for Epidemiologic Studies of the Elderly (EPESE) short physical performance battery. Physiologic capacity was measured by strength (one repetition maximum), dynamic balance (tandem walk), gait speed (2-meter walk), and cardiovascular endurance (6-minute walk). RESULTS: 70 participants (97%) completed the 6-month trial. Compliance with study interventions within each group ranged from 75% in controls to 82% in exercisers. PPT increased by 6.1 +/- 13.4% in exercisers and decreased by 2.8 +/- 13.6% in controls (p =.02). EPESE improved by 26.2 +/- 37.5% in exercisers and decreased by 1.2 +/- 22.1% in controls (p =.001). Dynamic balance improved by 33.8 +/- 14.4% in exercisers versus 11.5 +/- 23.7% in controls (p =.0002). There were no differences between groups in the change in strength, gait speed, or cardiovascular endurance. CONCLUSIONS: Minimally supervised exercise is safe and can improve functional performance in elderly individuals. The improvements in functional performance occurred along with improvements in balance but without a significant change in muscle strength or endurance.

Activities of Daily Living↗

PubMed2002

A home-based nutrition intervention to increase consumption of fruits, vegetables, and calcium-rich foods in community dwelling elders.

OBJECTIVE: To increase fruit, vegetable, and calcium-rich food consumption in community-dwelling, functionally impaired elderly. DESIGN: Six-month, home-based nutrition intervention study. SUBJECTS: Seventy men and women older than age 69 years were randomized to either a nutrition education intervention (n = 38) or a control group that received an exercise intervention (n = 32). INTERVENTION: Nutrition education was designed to increase fruit, vegetable, and calcium-rich food consumption. MAIN OUTCOME MEASURES: Food intake was assessed by a food frequency questionnaire. Fasting blood measures of nutrients and carotenoids were performed. Statistical Analysis Two-group randomized controlled trial with pre-test and post-test design and intention-to-treat analysis. Analysis of covariance to was used to assess differences between the two groups. Baseline and change partial correlation coefficients were performed between intake and blood nutrient levels. Paired t tests were conducted to test within-group changes. RESULTS: Compared with the exercise group, subjects in nutrition group increased their self-reported intake of fruits by 1.1 +/- 0.2 (mean +/- SEM) servings per day (2.8 to 3.9, P = .01), vegetables 1.1 +/- 0.2 servings per day (2.3 to 3.4, P = .001), and milk/dairy 0.9 +/- 0.2 servings per day (3.0 to 3.9, P = .001). There was an increase in the dietary intake of alpha-carotene and beta-carotene in the nutrition group and this correlated with the increase in blood concentrations of alpha-carotene and beta-carotene (P < or = .02; r = 0.33 and r = 0.33, respectively). CONCLUSION: The results of this study suggest that it is possible to improve the dietary intake of community dwelling elders to include more fruits, vegetables, and calcium-rich foods. Recommendations for increasing consumption of fruits, vegetables, and calcium-rich foods should be specific and individualized to meet the dietary pattern and lifestyle of the individual. Compliance should be encouraged with record keeping as well as through continuous monitoring and positive reinforcement.

Aged↗

PubMed2002

A randomized controlled trial of resistance exercise training to improve glycemic control in older adults with type 2 diabetes.

OBJECTIVE: To determine the efficacy of high-intensity progressive resistance training (PRT) on glycemic control in older adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: We performed a 16-week randomized controlled trial in 62 Latino older adults (40 women and 22 men; mean +/- SE age 66 +/- 8 years) with type 2 diabetes randomly assigned to supervised PRT or a control group. Glycemic control, metabolic syndrome abnormalities, body composition, and muscle glycogen stores were determined before and after the intervention. RESULTS: Sixteen weeks of PRT (three times per week) resulted in reduced plasma glycosylated hemoglobin levels (from 8.7 +/- 0.3 to 7.6 +/- 0.2%), increased muscle glycogen stores (from 60.3 +/- 3.9 to 79.1 +/- 5.0 mmol glucose/kg muscle), and reduced the dose of prescribed diabetes medication in 72% of exercisers compared with the control group, P = 0.004-0.05. Control subjects showed no change in glycosylated hemoglobin, a reduction in muscle glycogen (from 61.4 +/- 7.7 to 47.2 +/- 6.7 mmol glucose/kg muscle), and a 42% increase in diabetes medications. PRT subjects versus control subjects also increased lean mass (+1.2 +/- 0.2 vs. -0.1 +/- 0.1 kg), reduced systolic blood pressure (-9.7 +/- 1.6 vs. +7.7 +/- 1.9 mmHg), and decreased trunk fat mass (-0.7 +/- 0.1 vs. +0.8 +/- 0.1 kg; P = 0.01-0.05). CONCLUSIONS: PRT as an adjunct to standard of care is feasible and effective in improving glycemic control and some of the abnormalities associated with the metabolic syndrome among high-risk older adults with type 2 diabetes.

Aged↗

PubMedDate not supplied

Diabetes control with physical activity and exercise.

Regular physical activity and exercise are important components in the prevention of diabetes. In addition to lowering blood glucose, exercise improves insulin action, contributes to weight loss, and reduces several risk factors for cardiovascular disease. The association between increased levels of physical activity and a reduced occurrence of diabetes' long-term complications suggests that regular physical activity has a protective role. This association has been shown in the Diabetes Prevention Program. In which physical activity in the form of walking for 30 minutes/day on most days of the week was encouraged. Most people with diabetes, like people without diabetes, fall to meet national physical activity goals. Sedentary lifestyles have been linked to 23% of deaths from leading chronic diseases, including heart disease and diabetes. Given the epidemic nature of diabetes in the world during the 21st century, diabetes management through physical activity and structured exercise should be considered an adjunct to diabetes management. While both endurance and resistance exercise can improve insulin action and glucose homeostasis, the two forms of exercise differ significantly in how they alter muscle metabolism and structure. Understanding the beneficial effects of exercise, as well as the mechanisms for adopting a physically active lifestyle, is important for the management of diabetes mellitus. Despite the well-known benefits of exercise, patient education, paired with the implementation and promotion of safe and sustainable habits of physical activity for individuals with diabetes, is still inadequate.

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