Parents' emotion expression as a predictor of child's social competence: children with or without intellectual disability

BACKGROUND

Parents' expression of positive emotion towards children who are typically developing (TD) is generally associated with better social development. However, the association between parents' negative emotion expression and social development can be positive or negative depending upon a number of factors, including the child's emotion regulation abilities. Given the lower emotion regulation capabilities of children with intellectual disability (ID), we hypothesised that parents' negative emotion expression would be associated with lower social development in children with ID compared to those with TD.

METHODS

Participants were 180 families of children with or without ID enrolled in a longitudinal study. Parents' positive and negative affect were coded live from naturalistic home interactions at child ages 5-8 years, and child's social skills were measured by using mother report at child ages 6-9 years. We examined mothers' and fathers' emotion expression as a time-varying predictor of social skills across ages 5-9 years.

RESULTS

Mothers, but not fathers, expressed less positive affect and more negative affect with ID group children. Parents' positive affect expression was related to social skills only for TD children, with mothers' positive affect predicting higher social skills. Contrary to expectations, fathers' positive affect predicted lower social skills. Parents' negative affect predicted significantly lower social skills for children with ID than for children with TD.

CONCLUSIONS

Findings support the theory that low to moderate levels of negative expression may be less beneficial or detrimental for children with ID compared to children with TD. Implications for further research and intervention are discussed.

A lifetime of low-risk behaviors among HIV-positive Latinas in Los Angeles

The objective is to assess the differences in lifetime and current transmission risk behaviors of HIV-positive and HIV-negative Latinas. In 2005-2006, 214 HIV-positive Latinas were recruited from systems of care and 111 HIV-negative Latina-matched controls were interviewed in Los Angeles, CA regarding lifetime and recent sexual and drug-taking risk behaviors. Multivariate OLS regression and logistic regression models were used to assess differences in lifetime and current transmission risk. There was no significant difference between the two groups with respect to lifetime exposure through injection drug use. HIV-positive Latinas reported significantly more lifetime sexual partners than HIV-negative Latinas. Rates of current sexual activity were not significantly different across the two groups. HIV-positive Latinas were less likely to report recent unprotected sex relative to HIV-negative Latinas. In Los Angeles, HIV-positive and HIV-negative Latinas were very similar with respect to transmission risk. The challenges these findings pose to prevention efforts that target Latinas and suggestions for new interventions are discussed.

Pre-treatment levels of circulating free IGF-1 identify NSCLC patients who derive clinical benefit from figitumumab

BACKGROUND

Phase III trials of the anti-insulin-like growth factor type 1 receptor (IGF-IR) antibody figitumumab (F) in unselected non-small-cell lung cancer (NSCLC) patients were recently discontinued owing to futility. Here, we investigated a role of free IGF-1 (fIGF-1) as a potential predictive biomarker of clinical benefit from F treatment.

MATERIALS AND METHOD

Pre-treatment circulating levels of fIGF-1 were tested in 110 advanced NSCLC patients enrolled in a phase II study of paclitaxel and carboplatin given alone (PC) or in combination with F at doses of 10 or 20 mg kg(-1) (PCF10, PCF20).

RESULTS

Cox proportional hazards model interactions were between 2.5 and 3.5 for fIGF-1 criteria in the 0.5-0.9 ng ml(-1) range. Patients above each criterion had a substantial improvement in progression-free survival on PCF20 related to PC alone. Free IGF-1 correlated inversely with IGF binding protein 1 (IGFBP-1, ρ=-0.295, P=0.005), and the pre-treatment ratio of insulin to IGFBP-1 was also predictive of F clinical benefit. In addition, fIGF-1 levels correlated with tumour vimentin expression (ρ=0.594, P=0.021) and inversely with E-cadherin (ρ=-0.389, P=0.152), suggesting a role for fIGF-1 in tumour de-differentiation.

CONCLUSION

Free IGF-1 may contribute to the identification of a subset of NSCLC patients who benefit from F therapy.

Family-based processes associated with adolescent distress, substance use and risky sexual behavior in families affected by maternal HIV

The present study investigated how maternal HIV and mediating family processes are associated with adolescent distress, substance use, and risky sexual behavior. Mother-adolescent (ages 12-21) dyads (N = 264) were recruited from neighborhoods where the HIV-affected families resided (161 had mothers with HIV). Mediating family processes were youth aggressive conflict style, maternal bonding, maternal role reversal expectations, and overall family functioning. Results of structural equation modeling indicated that youth aggressive conflict resolution style was strongly associated with adolescent distress, substance use, and risky sexual behavior. In HIV-affected families, youth less frequently reported using an aggressive conflict resolution style and more frequently reported positive maternal bonds; their mothers reported less positive family functioning than control families. Finally, maternal distress indirectly affected adolescent distress and risk behavior via youth aggressive conflict resolution style.

Recombinant NY‐ESO‐1 Cancer Antigen: Production and Purification under cGMP Conditions

The cancer-testis antigen, NY-ESO-1, has been engineered into a bacterial expression plasmid which incorporates a His6-tag. The plasmid was transfected into E. coli strain BL21 and Master and Working cell banks generated from this expression system. Three 15-litre fermentations were performed under cGMP (code of Good Manufacturing Practice) conditions and the crude NY-ESO-1 tagged protein isolated as solubilised inclusion bodies. A three-step cGMP chromatography process (immobilised metal affinity, anion exchange, and hydrophobic interaction) was utilised to purify the protein. The purified NY-ESO-1 is being used in early stage human cancer vaccine trials in Australia and the U.S.A.

Madelung's deformity: a review

Madelung's deformity is a rare condition of the wrist characterized by a shortened distal radius with volar-ulnar curvature and a dorsally prominent distal ulna. It occurs predominantly in adolescent females who present with pain, decreased wrist mobility, and deformity. Although its aetiology remains unclear, its treatment is becoming more refined. Several different surgical techniques have recently been described in the literature. This review addresses Madelung's deformity and suggests an algorithm for management based on current literature and the authors' own clinical experience.

Use of Gascon and Pronase either as a pre-endoscopic drink or as targeted endoscopic flushes to improve visibility during gastroscopy: a prospective, randomized, controlled, blinded trial

OBJECTIVE

To assess whether endoscopic flushes of the bubble-bursting agent Gascon and the mucolytic agent Pronase are as effective in terms of improving endoscopic mucosal visibility as a pre-endoscopic drink of the same agents.

MATERIAL AND METHODS

A total of 112 patients attending a Japanese tertiary referral centre for upper gastrointestinal endoscopy were randomized to receive either the standard Japanese procedure of a pre-endoscopic drink of water containing Gascon and Pronase with endoscopic flushes of 20-ml aliquots of water, or no pre-endoscopic therapy but endoscopic flushes of 20-ml aliquots of water containing Gascon, with or without Pronase as necessary.

RESULTS

Visibility scores were significantly better in the pre-endoscopic drink group than in either of the endoscopic flush groups. The group receiving a pre-endoscopic drink required fewer flushes during the procedure and there was no difference in the endoscopic time between the three groups.

CONCLUSIONS

Our results suggest that endoscopic spraying of these bubble-bursting and mucolytic agents is not able to offer equivalent improvements in endoscopic mucosal visibility when compared with the standard Japanese therapy of a pre-endoscopic drink of these agents. The addition of Pronase to the spray solution had no measurable benefit over Gascon alone. We therefore cannot recommend endoscopic spraying of mucous clearing agents over their use as a pre-endoscopic drink.

Multicentre phase II studies evaluating imatinib plus hydroxyurea in patients with progressive glioblastoma

Background:

We evaluated the efficacy of imatinib mesylate in addition to hydroxyurea in patients with recurrent glioblastoma (GBM) who were either on or not on enzyme-inducing anti-epileptic drugs (EIAEDs).

Methods:

A total of 231 patients with GBM at first recurrence from 21 institutions in 10 countries were enrolled. All patients received 500 mg of hydroxyurea twice a day. Imatinib was administered at 600 mg per day for patients not on EIAEDs and at 500 mg twice a day if on EIAEDs. The primary end point was radiographic response rate and secondary end points were safety, progression-free survival at 6 months (PFS-6), and overall survival (OS).

Results:

The radiographic response rate after centralised review was 3.4%. Progression-free survival at 6 months and median OS were 10.6% and 26.0 weeks, respectively. Outcome did not appear to differ based on EIAED status. The most common grade 3 or greater adverse events were fatigue (7%), neutropaenia (7%), and thrombocytopaenia (7%).

Conclusions:

Imatinib in addition to hydroxyurea was well tolerated among patients with recurrent GBM but did not show clinically meaningful anti-tumour activity.

Lessons Learned from "integrating" intensive family-based interventions into medical care settings for mothers living with HIV/AIDS and their adolescent children

Centers for Disease Control and Prevention (CDC) has recommended integrating behavioral interventions into medical care settings for persons living with HIV. Delivering an intensive, family-based intervention for mothers living with HIV (MLH) (n = 173) and their adolescent children (n = 116) integrated into medical care was problematic. Despite the fact that nearly half of MLH were recruited at HIV/AIDS clinics, community centers and children's hospitals were the most popular and most successful sites for the delivery of the intervention. We provide recommendations for how to integrate intensive interventions into medical care, given the needs of MLH, their adolescents, and the organizations serving them.

Endogenous volatile organic compounds in breath and blood of healthy volunteers: examining breath analysis as a surrogate for blood measurements

To investigate the premise that levels of endogenous volatile organic compounds (VOC) in breath reflect those in blood, the concentration of acetone and isoprene were measured in radial arterial blood, peripheral venous blood and breath samples from ten healthy volunteers. Coefficients of repeatability as a percentage of mean are less than 30% in breath but greater than 70% in blood. The volunteer-mean ratios of arterial to venous blood concentration are 1.4 (0.9-2.1) for acetone and 0.55 (0.3-1.0) for isoprene. Concentration in breath showed a significant inter-subject correlation with concentration in arterial blood (CAB) for acetone but not for isoprene. Arterial blood/breath ratios are 580 (280-1060) for acetone and 0.47 (0.22-0.77) for isoprene. The sample-mean blood/breath ratio was used to calculate an estimate of CAB and the standard deviation of this estimate was lower than that of arterial blood measured directly. For most subjects, estimated CAB was within uncertainty limits of the actual CAB. Owing to the poor repeatability of VOC concentrations from consecutive blood samples, and the capacitive effects of the lung, this study suggests that breath VOC measurements may provide a more consistent measure than blood measurements for investigating underlying physiological function or pathology within individuals.

Clostridium difficile ribotypes 027 and 106: clinical outcomes and risk factors

The present study investigates risk factors for onset of Clostridium difficile-associated diarrhoea, specific ribotype and environmental spore contamination in a District General Hospital in South East England. C. difficile isolates were ribotyped from 97 diarrhoeal cases, following detection of C. difficile toxin from faecal specimens by enzyme immunoassay (Health Protection Agency, Southampton). The isolates were tested for various antimicrobial susceptibilities by E-test. Cases were assessed for prior antibiotic use and followed up for clinical outcomes. Controls were matched for age, sex, ward, length of stay and comorbidity to identify any antibiotic risk factors using conditional logistic regression analysis. Environmental sampling on wards was performed with cycloserine-cefoxitin-egg yolk agar. Forty-five percent C.difficile isolates ribotyped as 027, 39% as 106 and 10% as 001. All ribotypes were resistant to ciprofloxacin, erythromycin and cefotaxime but remained susceptible to metronidazole and vancomycin. The crude (death within 28 days) and early (death within 72h) mortalities were 23% and 11% for the 027 strain, whereas for the 106 ribotype they were 11% and 3%, respectively. The case-control study identified ciprofloxacin usage for >7 days as a significant risk factor (adjusted odds ratios of 3.72; 95% CI: 1.38-10.02; P=0.019). Environmental sampling revealed the presence of spores on faecally contaminated equipment such as commodes and bedpan shells, which persisted after cleaning. Ciprofloxacin appears to encourage C.difficile-associated diarrhoea and should be restricted to short courses. Cleaning agents for clinical equipment must have sporicidal activity to prevent cross-transmission.

Experimental feasibility studies on a SPECT tomograph for BNCT dosimetry

This article reports on the development of a prototype of a SPECT tomograph system for online dosimetry in BNCT based on LaBr(3)(Ce) scintillation detectors. The setup shielding was optimized to be used in the accelerator based BNCT facility of the University of Birmingham. The system was designed and built. An image of a (241)Am point source was reconstructed. A projection of a phantom with two tumors with 400 microg/g of (10)B was measured at the BNCT facility.

Small SRS photon field profile dosimetry performed using a PinPoint air ion chamber, a diamond detector, a novel silicon-diode array (DOSI), and polymer gel dosimetry. Analysis and intercomparison

Small photon fields are increasingly used in modern radiotherapy and especially in IMRT and SRS/SRT treatments. The uncertainties related to small field profile measurements can introduce significant systematic errors to the overall treatment process. These measurements are challenging mainly due to the absence of charged particle equilibrium conditions, detector size and composition effects, and positioning problems. In this work four different dosimetric methods have been used to measure the profiles of three small 6 MV circular fields having diameters of 7.5, 15.0, and 30.0 mm: a small sensitive volume air ion chamber, a diamond detector, a novel silicon-diode array (DOSI), and vinyl-pyrrolidone based polymer gel dosimeter. The results of this work support the validity of previous findings, suggesting that (a) air ion chambers are not suitable for small field dosimetry since they result in penumbra broadening and require significant corrections due to severe charged particle transport alterations; (b) diamond detectors provide high resolution and rather accurate small field profile measurements, as long as positioning problems can be addressed and the necessary dose rate corrections are correctly applied; and (c) the novel silicon-diode array (DOSI) used in this study seems to be adequate for small field profile measurements overcoming positioning problems. Polymer gel data were assumed as reference data to which the other measurement data were compared both qualitatively and quantitatively using the gamma-index concept. Polymer gels are both phantom and dosimeter, hence there are no beam perturbation effects. In addition, polymer gels are tissue equivalent and can provide high-spatial density and high-spatial resolution measurements without positioning problems, which makes them useful for small field dosimetry measurements. This work emphasizes the need to perform beam profile measurements of small fields (for acceptance, commissioning, treatment planning systems data feed, and periodic quality assurance purposes) using more than one dosimetric method. The authors believe this to be a safe way towards the reduction of the overall uncertainty related to SRS/SRT treatments.

Development of a protocol to measure volatile organic compounds in human breath: a comparison of rebreathing and on-line single exhalations using proton transfer reaction mass spectrometry

Analysis of volatile organic compounds (VOCs) on human breath has great potential as a non-invasive diagnostic technique. It is, therefore, surprising that no single, standard procedure has evolved for breath sampling. Here we present a novel repeated-cycle isothermal rebreathing method, where one cycle comprises five rebreaths, which could be adopted for breath analysis of VOCs. For demonstration purposes, we present measurements of three common breath VOCs: isoprene, acetone and methanol. Their concentrations measured in breath are shown to increase with number of rebreaths until a plateau value is reached by at least 20 rebreaths. The average ratio of plateau concentration to single mixed expired breath concentration was found to be 1.92 +/- 0.57 for isoprene, 1.25 +/- 0.13 for acetone and 1.12 +/- 0.12 for methanol (mean +/- standard deviation). Measurements from on-line single exhalations are presented which demonstrate a positive slope in the time-dependent expirograms of isoprene and acetone. The slope of the isoprene expirogram is persistently linear and the end-expired concentration of isoprene is highly variable in the same subject depending on the duration of exhalation. End-expired values of acetone are not as sensitive to the length of exhalation, and are the same to within measurement uncertainty for any duration of exhalation for any subject. It is concluded that uncontrolled single on-line exhalations are not suitable for the reliable measurement of isoprene in the breath and that rebreathing can be the basis of an easily tolerated protocol for the reliable collection of breath samples.

Arthrographic distension for adhesive capsulitis (frozen shoulder)

BACKGROUND

Adhesive capsulitis (frozen shoulder or painful stiff shoulder) is characterised by spontaneous onset of shoulder pain accompanied by progressive stiffness and disability. It is usually self-limiting but often has a prolonged course over two to three years.

OBJECTIVES

To determine the effectiveness and safety of arthrographic distension of the glenohumeral joint in the treatment of adults with adhesive capsulitis.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Review Group Register, CENTRAL, MEDLINE, CINAHL, and EMBASE to November 2006, unrestricted by date or language.

SELECTION CRITERIA

We included randomised controlled trials and controlled clinical trials comparing arthrographic distension with placebo or other interventions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data.

MAIN RESULTS

Five trials with 196 people were included. One three-arm trial (47 participants) compared arthrographic distension using steroid and air to distension using air alone and to steroid injection alone. One trial (46 participants) compared arthrographic distension using steroid and saline to placebo. Two trials (45 and 22 participants) compared arthrographic distension using steroid to steroid injection alone. One trial (36 participants) compared arthrographic distension using steroid and saline plus physical therapy to physical therapy alone. Trials included similar study participants, but quality and reporting of data were variable. Only one trial was at low risk of bias. No meta-analysis was performed.The trial with low risk of bias demonstrated that distension with saline and steroid was better than placebo for pain (number needed to treat to benefit (NNTB) = 2), function (NNTB = 3) and range of movement at three weeks. This benefit was maintained at six and 12 weeks only for one of two scores measuring function (NNT = 3). A second trial with high risk of bias also reported that distension combined with physical therapy improved range of movement and median percent improvement in pain (but not pain score) at eight weeks compared to physical therapy alone. Three further trials, all at high risk of bias, reported conflicting, variable effects of arthrographic distension with steroid compared to distension alone, and arthrographic distension with steroid compared to intra-articular steroid injection. The trials reported a small number of minor adverse effects, mainly pain during and after the procedure.

AUTHORS' CONCLUSIONS

There is "silver" level evidence that arthrographic distension with saline and steroid provides short-term benefits in pain, range of movement and function in adhesive capsulitis. It is uncertain whether this is better than alternative interventions.

The association between traumatic experience, paranoia and hallucinations: a test of the predictions of psychological models

OBJECTIVE

The current study investigated the relationship between trauma and predisposition to hallucinations and to paranoia in a non-clinical sample.

METHOD

A total of 228 students completed online measures of trauma, post traumatic stress disorder (PTSD), schematic beliefs, perceptual anomalies, and predisposition to hallucinations and paranoia.

RESULTS

Associations were found between negative schematic beliefs, PTSD and predisposition to both paranoia and hallucinations. PTSD reexperiencing-symptoms were most strongly associated with a predisposition to hallucinations. Negative beliefs about self and others were most strongly associated with a predisposition to paranoia.

CONCLUSION

The results provide support for the prediction that there may be two routes between trauma and predisposition to psychosis. Clear support was found for a link between trauma and psychosis mediated by negative beliefs about self and others. There may also be a direct association between re-experiencing symptoms and hallucinations.

WITHDRAWN: Interventions for shoulder pain

BACKGROUND

Shoulder pain is a common problem and although there are many accepted standard forms of conservative therapy for shoulder disorders including non-steroidal anti-inflammatory drugs, glucocorticosteroid injections, oral glucocorticosteroid medication, manipulation under anaesthesia, physical therapy, hydrodilatation (distension arthrography) and surgery, evidence of their efficacy is not well established.

OBJECTIVES

To review the efficacy of common interventions for shoulder pain.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group trials register, Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, and Science Citation Index) up to May 1998, and hand searched major textbooks, bibliographies of relevant literature, the fugitive literature, and the subject indices of relevant journals including: American College of Rheumatology;British College of Rheumatologists; the Biennial Conference of the Manipulative Physiotherapy Association of Australia;International Federation of Manual Therapists conference proceedings; British Orthopaedic Association;and American Orthopaedic Association.

SELECTION CRITERIA

Each identified study was assessed for possible inclusion by two independent reviewers based on the blinded methods sections. The determinants for inclusion were that the trial include an intervention of interest (non-steroidal anti-inflammatory drugs, intra-articular or subacromial glucocorticosteroid injection, oral glucocorticosteroid treatment, physiotherapy, manipulation under anaesthesia, hydrodilatation, or surgery); that treatment allocation was randomized; and that the outcome assessment was blinded.

DATA COLLECTION AND ANALYSIS

Methodological quality was assessed by two independent, blinded reviewers. Data relating to selection criteria, outcome measurement and treatment effect was extracted from the blinded trials. Range of motion scores were entered as degrees of restriction to movement, and all pain and overall effect scores were transformed to 100 point scales. For continuous outcome measures, where standard deviation was not reported it was either calculated from the raw data or converted from standard error of the mean. If neither of these were reported, authors were contacted in an effort to obtain the missing values. Effect sizes were calculated and combined in a pooled analysis if study population, endpoint and intervention were comparable.

MAIN RESULTS

Thirty one trials met inclusion criteria. Mean methodological quality score was 16.8 (9.5 - 22) out of possible score of 40. Selection criteria varied widely even for the same diagnostic label. There was no uniformity in outcome measures used and their measurement properties were rarely reported. Effect sizes for individual trials were small (-1.4 to 3.0). The results of only three studies investigating "rotator cuff tendonitis" could be pooled. Benefit of subacromial steroid injection over placebo for improving range of abduction (weighted difference between means (WMD) 35 degrees , 95% CI 14 to 55) was the only positive finding.

AUTHORS' CONCLUSIONS

There is little evidence to support or refute the efficacy of common interventions for shoulder pain. As well as, the need for further well designed clinical trials, more research is needed to establish a uniform method of defining shoulder disorders and developing outcome measures which are valid, reliable and responsive in these study populations.

Phase I study of sapacitabine, an oral nucleoside analogue, in patients with advanced leukemias or myelodysplastic syndromes

7063

Background: Sapacitabine, a 2′-deoxycytidine nucleoside analogue with unique ability to induce G2 cell cycle arrest and cause irreparable single-strand DNA breaks, is undergoing clinical evaluation for the treatment of cancer. The recommended Phase II dose (RD) in patients with advanced solid tumors was 75 mg b.i.d.×7 days orally every 21 days. The major DLT was myelosuppression. Here, we present the initial results of a Phase I study of sapacitabine in patients with advanced leukemias or MDS. The primary objective was to define the MTD of the above dosing schedule and the secondary objectives were to characterize the PK/PD effects of sapacitabine and its major metabolite CNDAC. Methods: Eligible patients had relapsed/refractory leukemias or MDS, or untreated disease if not willing to proceed with conventional systemic chemotherapy, adequate organ functions and performance status of 0–2. At least 3 patients were enrolled at each dose level. The MTD was the highest dose level at which =2/6 patients experienced a DLT during the first treatment cycle. Results: Twenty- nine patients received sapacitabine. Median age was 64 (range: 36 - 91). The majority of patients had AML (n=24) or MDS (n=4). Median number of prior chemotherapies was 2 (range: 0 - 6). MTD was reached at the dose level of 375 mg b.i.d. with 2/7 patients experienced the DLT of small bowel obstruction (n=1) or neutropenic colitis (n=1). One patient died from complications of neutropenic colitis. Common non-hematologic adverse events (all grades, regardless of causality) included nausea, vomiting, diarrhea, anorexia, alopecia, and fatigue, most of which were mild to moderate in intensity. PK and PD data are being analyzed. To date, 7 patients (5 AML, 2 MDS) had a reduction in bone marrow blast counts to = 5% including 1 CR in refractory AML with incomplete platelet recovery and 1 CR in relapsed MDS. In addition, 2 AML patients with relapsed leukemia cutis had a significant reduction in leukemia infiltrates in skin. Conclusion: The RD of sapacitabine for the b.i.d.×7 days every 21 days schedule is 325 mg b.i.d. The DLT is gastrointestinal toxicity. Sapacitabine is well tolerated and has promising antileukemic activity in patients with relapsed or refractory AML and MDS.

No significant financial relationships to disclose.

Long-term respiratory support in children with giant omphalocele

Omphalocele is one of the most common fetal abdominal wall defects. When this defect is of giant size, significant respiratory compromise may occur and impact on prognosis. We present three infants with giant omphalocele, highlighting the potential need for ongoing ventilatory support after the neonatal period in children born with this condition. The three cases had very different outcomes but all had significant ventilatory insufficiency and required substantial respiratory support at least into the second year of life. The possibility of a requirement for long-term ventilatory support should be discussed with families at antenatal diagnosis. A conservative surgical approach, together with early monitoring for hypoventilation and screening for the development of pulmonary hypertension is indicated for these children to limit morbidity. We suggest early tertiary respiratory input and advocate for a specific case manager to oversee the regional care of these children.

Effect of type 2 diabetes mellitus on exercise intolerance and the physiological responses to exercise in peripheral arterial disease

AIMS/HYPOTHESIS

There are conflicting data about the effect of type 2 diabetes mellitus on exercise tolerance in peripheral arterial disease. To elucidate this problem, we compared the tolerance and physiological responses to treadmill and cycle exercise in 31 patients with peripheral arterial disease and intermittent claudication.

MATERIALS AND METHODS

One group of these patients had type 2 diabetes (n = 12) and its members were matched for sex and age with a group of patients who did not have diabetes (n = 12). Since BMI and body weight were greater in the diabetic group (28.4 +/- 3.7 vs 25.2 +/- 2.4 kg/m(2); 84.0 +/- 14.6 vs 73.8 +/- 8.0 kg), we also studied a third, 'heavy' group of non-diabetic patients with claudication of similar age (n = 7; BMI = 30.9 +/- 5.3 kg/m(2); body weight = 85.2 +/- 8.2 kg).

RESULTS

Compared with the 'light' non-diabetic group, maximum treadmill times were shorter for the diabetic and heavy non-diabetic groups (1,448 vs 845 and 915 s; ANOVA p = 0.01); maximum cycle time also tended to be shorter (ANOVA, p = 0.08) in the diabetic and heavy non-diabetic groups (median = 1,231 vs 730 and 797 s). The majority of physiological responses assessed were not different between the groups, although the time constant of oxygen uptake during submaximal treadmill and cycle exercise was significantly larger (ANOVA p < 0.05) for the diabetic group.

CONCLUSIONS/INTERPRETATION

These data demonstrate that exercise tolerance is lower in diabetic than non-diabetic patients with claudication, but that this difference is due to obesity rather than diabetes itself.