Associations between ankle-brachial index, diabetes, and sleep apnea in the Hispanic community health study/study of Latinos (HCHS/SOL) database.

BACKGROUND: Sleep apnea and diabetes mellitus (DM) negatively impact cardiovascular health. One important indicator of cardiovascular health is the Ankle-Brachial Index (ABI). Either low ABI or high ABI are signs of peripheral vascular impairment. Impaired vascular health and DM, together, might provoke sleep apnea; however, information regarding these relationships is limited. Therefore, this study aimed to investigate the association between ABI, DM status, and severity of obstructive sleep apnea in people of Hispanic/Latino descent who are diverse in culture, environmental exposures, nativity, socioeconomic status, and disease burden. METHODS: A cross sectional analysis from a multi-center epidemiologic study, Hispanic Community Health Study/Study of Latinos, was utilized and included 3779 participants (mean age 55.32 ± 7.67, females 57.9%). The sample was divided into 4 groups based on the American Diabetes Association diagnostic guidelines (no DM or DM), and the ABI status (normal and abnormal). Multiple linear regression analysis was used to determine the association of the four groups and other independent variables with severity of sleep apnea measured by apnea-hypopnea index. Kruskal-Wallis H test was used for comparisons between groups for the apnea-hypopnea index. The significant level was set at 0.01. RESULTS: There were significant differences between groups in the mean of apnea-hypopnea index (P < 0.001; no DM + normal ABI = 5.42 ± 9.66, no DM + abnormal ABI = 7.11 ± 11.63, DM + normal ABI = 10.99 ± 15.16, DM + abnormal ABI = 12.81 ± 17.80). Linear regression showed that DM and abnormal ABI were significantly associated with severe sleep apnea (ß = 3.25, P = 0.001) after controlling for age, sex, BMI, income, education, alcohol use, cigarette use, hypertension or related medication, stroke and statin use. CONCLUSION: These findings suggest that people with DM and abnormal ABI were more likely to have high apnea-hypopnea index compared to the other groups. We observed gradual increasing in the severity of sleep apnea from low abnormality groups to high abnormality groups for Hispanic/Latino. Further work should elucidate the association of DM, abnormal ABI and sleep apnea with longer term outcomes, and replicate this work in different populations.

A Subgroup of Chronic Low Back Pain Patients With Central Sensitization.

BACKGROUND: Our knowledge of central sensitization (CS) in chronic low back pain (CLBP) is limited. 2011 fibromyalgia criteria and severity scales (2011 FM survey) have been used to determine FM positive as a surrogate of CS. The major features of CS including widespread hyperalgesia and dysfunction of the descending inhibitory pathways can be identified by pressure pain threshold (PPT) and conditioned pain modulation (CPM) tests. The purpose of the study was to examine neurophysiological characteristics and psychosocial symptoms in a subgroup of FM-positive CLBP compared with FM-negative CLBP patients. METHODS: A total of 46 participants with CLBP and 22 pain-free controls completed outcome measures of the 2011 FM survey, PPT and CPM tests, and psychosocial questionnaires. Differences between FM-positive and FM-negative CLBP participants on these measures and correlations were analyzed. RESULTS: The 2011 FM survey identified 22 (48%) participants with CLBP as FM positive. FM-positive CLBP participants showed lower PPT values of the thumbnail (P=0.011) and lower back (P=0.003), lower CPM values of the thumbnail (P=0.002), and more severe pain catastrophizing, anxiety, and depression symptoms (P<0.05) than FM-negative CLBP participants. The 2011 FM scores were significantly correlated with the PPT and CPM values of the thumbnail and with psychosocial symptoms (P<0.001). DISCUSSION: Our findings suggest a subgroup of CLBP patients exhibiting with signs and symptoms of CS. Associations between subjective and objective CS measures indicate that the 2011 FM survey can be utilized to identify the presence of CS in CLBP in clinical practice.

Functional Reach, Depression Scores, and Number of Medications Are Associated With Number of Falls in People With Chronic Stroke.

BACKGROUND: Falls are a common adverse event among people with stroke. Previous studies investigating risk of falls after stroke have relied primarily on retrospective fall history ranging from 6-12 months recall, with inconsistent findings. OBJECTIVES: To identify factors and balance assessment tools that are associated with number of falls in individuals with chronic stroke. DESIGN: Secondary analysis of a randomized clinical trial. SETTING: Multisite academic and clinical institutions. PARTICIPANTS: Data from 181 participants with stroke (age 60.67 ± 11.77 years, post stroke 4.51 ± 4.78 years) were included. METHODS: Study participants completed baseline testing and were prospectively asked about falls. A multivariate negative binomial regression was used to identify baseline predictive factors predicting falls: age, endurance (6 minute walk test), number of medications, motor control (Fugl-Meyer lower extremity score), depression (Patient Health Questionnaire-9), physical activity (number of steps per week), and cognition (Mini Mental Status Exam score). A second negative binomial regression analysis was used to identify baseline balance assessment scores predicting falls: gait velocity (comfortable 10 Meter Walk), Berg Balance Scale (BBS), Timed Up and Go (TUG), and Functional Reach Test (FRT). Receiver operating characteristic (ROC) and area under the curve (AUC) were used to determine the cutoff scores for significant predictors of recurrent falls. MAIN OUTCOME MEASUREMENT: The number of falls during the 42-week follow-up period. RESULTS: Baseline measures that significantly predicted the number of falls included increased number of medications, higher depression scores, and decreased FRT. Cutoff scores for the number of medications were 8.5 with an AUC of 0.68. Depression scores differentiated recurrent fallers at a threshold of 2.5 scores with an AUC of 0.62. FRT differentiated recurrent fallers at a threshold of 18.15 cm with an AUC of 0.66. CONCLUSIONS: Number of medications, depression scores, and decreased FRT distance at baseline were associated with increased number of falls. Increased medications might indicate multiple comorbidities or polypharmacy effect; increased depression scores may indicate psychological status; and decreased functional reach distance could indicate dynamic balance impairments. LEVEL OF EVIDENCE: II.

Less is More in Diabetic Neuropathy Diagnosis: Comparison of Quantitative Sudomotor Axon Reflex and Skin Biopsy.

OBJECTIVES: To compare the frequency of abnormalities in epidermal nerve fiber density (ENFD) and quantitative sudomotor axon reflex (QSART) in patients with diabetic distal symmetric polyneuropathy (DSPN). METHODS: Nerve conduction studies, ENFD, and QSART data were obtained pre- and postexercise, in patients enrolled in a prospective diabetic neuropathy study. McNemar's test was applied to compare the yield of ENFD and QSART. RESULTS: Eighteen patients (58 ± 4 years) were enrolled, with 36 data collection points. In diabetic DSPN and diabetic large fiber DSPN (DSPN-L), abnormal ENFD (77% and 100% respectively) is more frequent than abnormal QSART (39% and 35%, respectively) (P value = 0.001 in diabetic DSPN and P value = 0.0002 in diabetic DSPN-L), whereas in diabetic small fiber DSPN (DSPN-S), both tests have similar yields (47%). CONCLUSIONS: ENFD has a high diagnostic yield in diabetic DSPN and DSPN-L. Including QSART data adds little to the sensitivity of EFND in DSPN-S.

Activity for Diabetic Polyneuropathy (ADAPT): Study Design and Protocol for a 2-Site Randomized Controlled Trial.

Background: Half of all patients with diabetes develop diabetic peripheral neuropathy (DPN), a complication leading to reduced mobility and quality of life. Although there are no proven pharmacologic approaches to reduce DPN risk or slow its progression, evidence suggests that physical activity may improve symptoms and enhance peripheral nerve regeneration. Objective: The aim of the study will be to determine the impact of an intense lifestyle intervention on neuropathy progression and quality of life in individuals with DPN. Design: The study will be a randomized controlled trial. Setting: The study will be conducted at 2 academic medical centers. Participants: The participants will be 140 individuals with type 2 diabetes and mild to moderate DPN. Intervention: The intervention group will receive 18 months of supervised exercise training, actigraphy-based counseling to reduce sedentary behavior, and individualized dietary counseling. Control group participants will receive diet and activity counseling at baseline and at 9 months. Measurements: The primary outcomes are neuropathy progression as measured by intraepidermal nerve fiber density in a distal thigh skin biopsy and the Norfolk Quality of Life-Diabetic Neuropathy score. Secondary outcomes include pain, gait, balance, and mobility measures. Limitations: Due to the combined intervention approach, this protocol will not be able to determine which intervention components influence outcomes. There also may be difficulty with participant attrition during the 18-month study intervention. Conclusions: The Activity for Diabetic Polyneuropathy (ADAPT) protocol resulted from a collaboration between physical therapists and neurologist researchers that includes as primary outcomes both a quality-of-life measure (NQOL-DN) and a physiologic biomarker (IENFD). It has the potential to demonstrate that an intensive lifestyle intervention may be a sustainable, clinically effective approach for people with DPN that improves patient outcomes and can have an immediate impact on patient care and future clinical trials.

Fatigue and related factors in people with type 2 diabetes.

PURPOSE: The purpose of this study was to examine the presence and severity of fatigue in people with type 2 diabetes. METHODS: The Fatigue Severity Scale (FSS), Fatigue Assessment Scale (FAS), and Visual Analog Fatigue Scale (VAFS) were administered by anonymous survey of 37 individuals with and 33 individuals without diabetes to assess the presence of fatigue. Data on age, gender, weight, height, year of diagnosis, and number/type of complications were also collected. Nonparametric tests tested for differences in fatigue measures between the groups, and distribution characteristics of the FAS, FSS, and VAFS scores were examined. Spearman rank correlation coefficients examined the relationships between the variables. RESULTS: People with diabetes scored higher on all 3 fatigue assessment scales as compared to controls (FAS: 25.11 vs 19.94, P = .001; FSS: 4.30 vs 2.59, P = .000; VAFS: 4.64 vs 1.75, P = .000). Data were normally distributed for FSS in the group with diabetes and the group without diabetes, and scores of FAS, FSS, and VAFS showed no ceiling effects. A positive correlation was noted between fatigue measures and number of complications (r = .482; P = .003). CONCLUSIONS: Higher levels of fatigue were noted in people with type 2 diabetes as compared to healthy age-matched control; however, the cause and impact of these changes remain unclear. FSS is a recommended tool for measuring fatigue in this population. Further studies are needed to explore the contributing factors to fatigue in those with diabetes.

Cardiorespiratory fitness in breast cancer survivors.

Maximal oxygen uptake (VO2max) has been used to assess risk for all-cause mortality and cardiovascular disease (CVD), and low VO2max has recently been associated with increased mortality from breast cancer. The purpose of this study was to determine the proportion of breast cancer survivors with 2 or more risk factors for CVD exhibiting a low VO2max and to determine whether sub-maximal endpoints which could be applied more readily to intervention research would correlate with the maximal treadmill test. We performed a single VO2max test on a treadmill with 30 breast cancer survivors age 30-60 (mean age 50.5 ± 5.6 years) who had 2 or more cardiac risk factors for CVD not related to treatment and who had received systemic therapy and or left chest radiation. Submaximal VO2 endpoints were assessed during the VO2max treadmill test and on an Arc trainer. Resting left ventricular ejection fraction (LVEF) was also assessed by echocardiogram (ECHO) or multi-gated acquisition scan (MUGA). A majority (23/30) of women had a VO2max below the 20th percentile based on their predicted normal values. The group mean resting LVEF was 60.5 ± 5.0%. Submaximal VO2 measures were strongly correlated with the maximal test including; 1) 85% age predicted maximum heart rate VO2 on treadmill, (r = .89; p < 0.001), 2) treadmill VO2 at anaerobic threshold (AT), (r = .83; p < 0.001), and 3) Arc VO2 at AT, (r = .80; p < 0.001). Breast cancer survivors with 2 or more CVD risk factors but normal LVEF had a low cardiorespiratory fitness level compared to normative values in the healthy population placing them at increased risk for breast cancer and cardiovascular mortality. Submaximal VO2 exercise testing endpoints showed a strong correlation with the VO2max test in breast cancer survivors and is a good candidate for testing interventions to improve cardiorespiratory fitness.

The effect of exercise on neuropathic symptoms, nerve function, and cutaneous innervation in people with diabetic peripheral neuropathy.

UNLABELLED: Although exercise can significantly reduce the prevalence and severity of diabetic complications, no studies have evaluated the impact of exercise on nerve function in people with diagnosed diabetic peripheral neuropathy (DPN). The purpose of this pilot study was to examine feasibility and effectiveness of a supervised, moderately intense aerobic and resistance exercise program in people with DPN. We hypothesized that the exercise intervention can improve neuropathic symptoms, nerve function, and cutaneous innervation. METHODS: A pre-test post-test design was used to assess change in outcome measures following participation in a 10-week aerobic and strengthening exercise program. Seventeen subjects with diagnosed DPN (8 males/9 females; age 58.4±5.98; duration of diabetes 12.4±12.2 years) completed the study. Outcome measures included pain measures (visual analog scale), Michigan Neuropathy Screening Instrument (MNSI) questionnaire of neuropathic symptoms, nerve function measures, and intraepidermal nerve fiber (IENF) density and branching in distal and proximal lower extremity skin biopsies. RESULTS: Significant reductions in pain (-18.1±35.5 mm on a 100 mm scale, P=.05), neuropathic symptoms (-1.24±1.8 on MNSI, P=.01), and increased intraepidermal nerve fiber branching (+0.11±0.15 branch nodes/fiber, P=.008) from a proximal skin biopsy were noted following the intervention. CONCLUSIONS: This is the first study to describe improvements in neuropathic and cutaneous nerve fiber branching following supervised exercise in people with diabetic peripheral neuropathy. These findings are particularly promising given the short duration of the intervention, but need to be validated by comparison with a control group in future studies.