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1.
Med Vet Entomol ; 34(4): 452-458, 2020 12.
Article in English | MEDLINE | ID: mdl-32697393

ABSTRACT

The spatial pattern of flea (Siphonaptera: Pulicidae) infestation risk in cats and dogs across Great Britain is quantified, using data collected from a national survey undertaken in 2018, with particular attention given to the association between insecticidal treatment and infestation risk. Flea infestation risk declined significantly from south to north. None of the factors: pet breed, sex, neutered status or whether the pet had been abroad, showed any relationship with the underlying geographic distribution, which is most likely to be associated with climatic factors. However, overall, only 23.6% of the cats and 35% of the dogs inspected had been treated with identifiable flea products that were still 'in date' at the point of inspection. The percentage of owners treating their pet broadly followed infestation risk. The insecticide fipronil is a common active in a wide range of flea treatments and was the most frequently applied insecticide class, particularly in cats. However, 62% of cats and 45% of dogs that had been treated with a fipronil-based product that was 'in date' at the point of inspection still had fleas. Persistent flea infestation is likely to be due to a range of factors, including compliance and application failure, but the data provide strong inferential evidence for a lack of efficacy of fipronil-based products. Given the ubiquity of flea infestation, this finding and the relatively low-level of treatment compliance, highlight a clear need for greater owner education about the importance of flea management and a better understanding of the efficacy of different products.


Subject(s)
Ctenocephalides/drug effects , Flea Infestations/veterinary , Pyrazoles/therapeutic use , Animals , Cat Diseases , Cats , Dog Diseases , Dogs , Flea Infestations/drug therapy , Geography , Insect Control , Insecticides/therapeutic use , Patient Compliance , United Kingdom
2.
Diabet Med ; 2018 May 08.
Article in English | MEDLINE | ID: mdl-29738609

ABSTRACT

AIM: To explore in a feasibility study whether 'e-cycling' was acceptable to, and could potentially improve the health of, people with Type 2 diabetes. METHODS: Twenty people with Type 2 diabetes were recruited and provided with an electric bicycle for 20 weeks. Participants completed a submaximal fitness test at baseline and follow-up to measure predicted maximal aerobic power, and semi-structured interviews were conducted to assess the acceptability of using an electric bicycle. Participants wore a heart rate monitor and a Global Positioning System (GPS) receiver in the first week of electric bicycle use to measure their heart-rate during e-cycling. RESULTS: Eighteen participants completed the study, cycling a median (interquartile range) of 21.4 (5.5-37.7) km per week. Predicted maximal aerobic power increased by 10.9%. Heart rate during electric bicycle journeys was 74.7% of maximum, compared with 64.3% of maximum when walking. Participants used the electric bicycles for commuting, shopping and recreation, and expressed how the electric bicycle helped them to overcome barriers to active travel/cycling, such as hills. Fourteen participants purchased an electric bicycle on study completion. CONCLUSIONS: There was evidence that e-cycling was acceptable, could increase fitness and elicited a heart rate that may lead to improvements in cardiometabolic risk factors in this population. Electric bicycles have potential as a health-improving intervention in people with Type 2 diabetes.

3.
Diabet Med ; 34(11): 1521-1531, 2017 11.
Article in English | MEDLINE | ID: mdl-28905421

ABSTRACT

AIM: Residual ß-cell function is present at the time of diagnosis with Type 1 diabetes. Preserving this ß-cell function reduces complications. We hypothesized that exercise preserves ß-cell function in Type 1 diabetes and undertook a pilot trial to address the key uncertainties in designing a definitive trial to test this hypothesis. METHODS: A randomized controlled pilot trial in adults aged 16-60 years diagnosed with Type 1 diabetes within the previous 3 months was undertaken. Participants were assigned to control (usual care) or intervention (exercise consultation every month), in a 1 : 1 ratio for 12 months. The primary outcomes were recruitment rate, drop out, exercise adherence [weeks with ≥ 150 min of self-reported moderate to vigorous physical activity (MVPA)], and exercise uptake in the control group. The secondary outcomes were differences in insulin sensitivity and rate of loss of ß-cell function between intervention and control at 6 and 12 months. RESULTS: Of 507 individuals who were approached, 58 (28 control, 30 intervention) entered the study and 41 completed it. Participants were largely white European males, BMI 24.8 ± 3.8 kg/m2 , HbA1c 75 ± 25 mmol/mol (9 ± 2%). Mean level of objectively measured MVPA increased in the intervention group (mean 243 to 273 min/week) and 61% of intervention participants reached the target of ≥ 150 min/week of self-reported MVPA on at least 42 weeks of the year. Physical activity levels fell slightly in the control group (mean 277 to 235 min of MVPA/week). There was exploratory evidence that intervention group became more insulin sensitive and required less insulin. However, the rate of loss of ß-cell function appeared similar between the groups, although the change in insulin sensitivity may have affected this. CONCLUSION: We show that it is possible to recruit and randomize people with newly diagnosed Type 1 diabetes to a trial of an exercise intervention, and increase and maintain their exercise levels for 12 months. Future trials need to incorporate measures of greater adherence to exercise training targets, and include more appropriate measures of ß-cell function. (Clinical Trials Registry No; ISRCTN91388505).


Subject(s)
Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 1/therapy , Exercise/physiology , Insulin-Secreting Cells/physiology , Adolescent , Adult , Age of Onset , Diabetes Mellitus, Type 1/metabolism , Exercise Therapy , Female , Humans , Male , Middle Aged , Pilot Projects , Young Adult
4.
J Assist Reprod Genet ; 33(8): 971-80, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27146151

ABSTRACT

PURPOSE: The purpose of this study was to evaluate whether outcomes are different if controlled ovarian stimulation (COS) is started in the luteal phase rather than the follicular phase. METHODS: A systematic review and meta-analysis was performed. Sixteen studies were included in the qualitative analysis, and eight studies with a total of 338 women were included in the quantitative analysis. RESULTS: Cycles initiated in the luteal phase were slightly longer (WMD 1.1 days, 95 % CI 0.39-1.9) and utilized more total gonadotropins (WMD 817 IU, 95 % CI 489-1144). However, no differences were noted in peak estradiol levels (WMD -411 pg/ml, 95 % CI -906-84.7) or in the total number of oocytes retrieved (WMD 0.52 oocytes, 95 % CI -0.74-1.7). There were slightly more mature oocytes retrieved in the luteal phase (WMD 0.77 oocytes, 95 % CI 0.21-1.3), and fertilization rates were significantly higher (WMD 10 %, 95 % CI 0.03-0.18). While only three studies reported pregnancy outcomes, no difference was noted in the FET pregnancy rates after COS in the luteal versus follicular phase (RR 0.95, 95 % CI 0.56-1.7). A post hoc power analysis revealed that a sample of this size was sufficient to detect a clinically meaningful difference of 2 oocytes retrieved with 93 % power. CONCLUSION: Although initiating COS in the luteal phase requires a longer stimulation and a higher dose of total gonadotropin, these differences are not clinically significant. Furthermore, COS initiated in the luteal phase does not compromise the quantity or quality of oocytes retrieved compared to outcomes of traditional stimulation in the follicular phase.


Subject(s)
Fertility Preservation/methods , Follicular Phase/physiology , Luteal Phase/physiology , Menstrual Cycle/physiology , Oocyte Retrieval/methods , Ovulation Induction/methods , Pregnancy Outcome , Adult , Cryopreservation , Female , Fertilization in Vitro/methods , Humans , Neoplasms/therapy , Oocytes , Pregnancy
5.
Scand J Med Sci Sports ; 25(5): 661-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25156494

ABSTRACT

The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys using their bicycle every day of the week displayed a higher carotid arterial compliance {standard beta 0.47 [95% confidence interval (CI) 0.07-0.87]} and distension [standard beta 0.38 (95% CI -0.04 to 0.81)]. Boys using their bicycle every day of the week furthermore displayed a lower Young's elastic modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may be beneficial to carotid arterial health among boys.


Subject(s)
Bicycling/physiology , Carotid Arteries/physiology , Vascular Stiffness , Adolescent , Bicycling/statistics & numerical data , Carotid Arteries/diagnostic imaging , Compliance , Cross-Sectional Studies , Denmark , Elastic Modulus , Female , Humans , Male , Self Report , Sex Factors , Ultrasonography
6.
Nutr Metab Cardiovasc Dis ; 24(9): 956-62, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24925122

ABSTRACT

BACKGROUND AND AIMS: We investigated whether objectively measured sedentary time was associated with markers of inflammation in adults with newly diagnosed type 2 diabetes. METHODS AND RESULTS: We studied 285 adults (184 men, 101 women, mean age 59.0 ± 9.7) who had been recruited to the Early ACTivity in Diabetes (Early ACTID) randomised controlled trial. C-reactive protein (CRP), adiponectin, soluble intracellular adhesion molecule-1 (sICAM-1), interleukin-6 (IL-6), and accelerometer-determined sedentary time and moderate-vigorous physical activity (MVPA) were measured at baseline and after six-months. Linear regression analysis was used to investigate the independent cross-sectional and longitudinal associations of sedentary time with markers of inflammation. At baseline, associations between sedentary time and IL-6 were observed in men and women, an association that was attenuated following adjustment for waist circumference. After 6 months of follow-up, sedentary time was reduced by 0.4 ± 1.2 h per day in women, with the change in sedentary time predicting CRP at follow-up. Every hour decrease in sedentary time between baseline and six-months was associated with 24% (1, 48) lower CRP. No changes in sedentary time between baseline and 6 months were seen in men. CONCLUSIONS: Higher sedentary time is associated with IL-6 in men and women with type 2 diabetes, and reducing sedentary time is associated with improved levels of CRP in women. Interventions to reduce sedentary time may help to reduce inflammation in women with type 2 diabetes.


Subject(s)
Biomarkers/blood , Diabetes Mellitus, Type 2/blood , Inflammation/blood , Motor Activity , Sedentary Behavior , Adiponectin/blood , Aged , Body Mass Index , C-Reactive Protein/metabolism , Cross-Sectional Studies , Diabetes Mellitus, Type 2/diagnosis , Female , Follow-Up Studies , Humans , Intercellular Adhesion Molecule-1/blood , Interleukin-6/blood , Male , Middle Aged , Waist Circumference
7.
BMJ Open ; 4(6): e004953, 2014 Jun 13.
Article in English | MEDLINE | ID: mdl-24928586

ABSTRACT

OBJECTIVES: Describe dietary intake of participants enrolled in a non-prescriptive dietary intervention and dietary changes at 6 months and explore whether these changes had a role in observed improvements in glycated haemoglobin (HbA1c), weight, lipids and blood pressure. DESIGN: Secondary analysis of data from the Early ACTivity in Diabetes randomised controlled trial. PARTICIPANTS: 262 patients with newly diagnosed type 2 diabetes randomised to the dietary intervention. OUTCOMES AND ANALYSIS: Changes in energy intake, macronutrients, fibre and alcohol and in weight, waist circumference, lipids, HbA1c and blood pressure at baseline and 6 months. Multivariate models were used to examine associations between dietary changes and metabolic variables. RESULTS: Men reported reducing mean energy intake from 1903±462 kcal to 1685 kcal±439 kcal (p<0.001), increasing carbohydrate intake from 42.4±6.6% to 43.8±6.6% (p=0.002) and reducing median alcohol intake from 13 (0-27) g to 5 (0-18) g (p<0.001). Women reported reducing mean energy intake from 1582±379 kcal to 1459±326 kcal (p<0.001) with no change to macronutrient distribution and alcohol. Fibre intake was maintained. In men (n=148), weak and clinically insignificant associations were found between increased carbohydrates and reduction in HbA1c (ß=-0.003 (-0.006, -0.001); p=0.009), increased fibre and reduction in total cholesterol (ß=-0.023 (-0.044, -0.002); p=0.033), decreased total fat and reduction in low-density lipoprotein (LDL)-cholesterol (ß=0.024 (0.006, 0.001); p=0.011), and decreased alcohol and reduction in diastolic blood pressure (ß=0.276 (0.055, 0.497); p=0.015). In women (n=75), associations were found between a decrease in transfats and reductions in waist circumference (ß=-0.029 (0.006, 0.052); p=0.015), total cholesterol (ß=0.399 (0.028, 0.770); p=0.036) and LDL cholesterol (ß=0.365 (0.042, 0.668); p=0.028). CONCLUSIONS: Clinically important metabolic improvements observed in a patient-centred dietary intervention were not explained by changes in macronutrients. However, a non-prescriptive approach may promote a reduction in total energy intake while maintaining fibre consumption. TRIAL REGISTRATION NUMBER: The Early ACTID trial number ISRCTN92162869.


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Feeding Behavior , Patient-Centered Care , Female , Humans , Male , Middle Aged
8.
Behav Res Ther ; 50(5): 323-32, 2012 May.
Article in English | MEDLINE | ID: mdl-22459731

ABSTRACT

Diabetic foot ulcers are a common, chronic and costly complication of Diabetes, with the greatest risk for ulceration being previous ulceration. Previous approaches to reducing re-ulceration risk have not, however, considered the psychosocial factors which may influence this risk. We reviewed the existing evidence in this area and developed a therapeutic model which informed the content, structure and format of a psychosocial intervention designed to modify the psychosocial risk factors associated with re-ulceration. The intervention was subjected to a qualitative evaluation in a feasibility study which involved a randomised controlled trial in which 10 individuals were randomised to receive the intervention and 5 individuals to usual care. Individuals in both arms participated in in-depth qualitative interviews after the first 10 weeks of the intervention and again after the final maintenance session. The intervention was perceived as acceptable and patients' reported evidence of sustained change in several of the psychosocial risks identified in the therapeutic model. These observations were supported in the descriptive findings obtained from questionnaires measuring mood, cognitions, behaviour and social support. The intervention appears to offer an acceptable and effective way of modifying the psychosocial risk factors associated with re-ulceration.


Subject(s)
Cognitive Behavioral Therapy/methods , Diabetic Foot/prevention & control , Aged , Aged, 80 and over , Diabetic Foot/psychology , Feasibility Studies , Female , Humans , Male , Middle Aged , Qualitative Research , Risk Factors , Surveys and Questionnaires , Treatment Outcome
9.
Diabetologia ; 55(3): 589-99, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22167127

ABSTRACT

AIMS/HYPOTHESIS: We investigated whether objectively measured sedentary time and interruptions in sedentary time are associated with metabolic factors in people with type 2 diabetes. METHODS: We studied 528 adults (30-80 years) with newly diagnosed type 2 diabetes, who were participants in a diet and physical activity intervention. Waist circumference (WC), fasting HDL-cholesterol, insulin and glucose levels, HOMA of insulin resistance (HOMA-IR) and physical activity (accelerometer) were measured at baseline and at 6 months follow-up. Linear regression models were used to investigate cross-sectional and longitudinal associations of accelerometer-derived sedentary time and breaks in sedentary time (BST) with metabolic variables. RESULTS: In cross-sectional analyses each hour of sedentary time was associated with larger WC (unstandardised regression coefficient [B] [95% CI] 1.89 cm [0.94, 2.83]; p < 0.001), higher insulin (B = 8.22 pmol/l [2.80, 13.65]; p = 0.003) and HOMA-IR (B = 0.42 [0.14, 0.70]; p = 0.004), and lower HDL-cholesterol (B = -0.04 mmol/l [-0.06, -0.01]; p = 0.005). Adjustment for WC attenuated all associations. Each BST was associated with lower WC (B = -0.15 cm [- 0.24, -0.05]; p = 0.003) and there was evidence of a weak linear association with HDL-cholesterol, but no association with insulin levels or HOMA-IR. Volume of sedentary time at baseline predicted HDL-cholesterol (B = -0.05 mmol/l [-0.08, -0.01]; p = 0.007), insulin levels (B = 8.14 pmol/l [0.1.51, 14.78]; p = 0.016) and HOMA-IR (B = 0.49 [0.08, 0.90]; p = 0.020) at 6 months, though not WC. Baseline BST did not substantially predict any metabolic variables at follow-up. No change was seen in sedentary time or BST between baseline and 6 months follow-up. CONCLUSIONS/INTERPRETATION: Higher sedentary time is associated with a poorer metabolic profile in people with type 2 diabetes.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/therapy , Motor Activity , Sedentary Behavior , Adult , Aged , Aged, 80 and over , Body Mass Index , Cholesterol, HDL/blood , Cohort Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , England , Female , Humans , Insulin/blood , Insulin Resistance , Longitudinal Studies , Male , Middle Aged , Overweight/complications , Patient Compliance , Time Factors , Young Adult
10.
Lancet ; 378(9786): 129-39, 2011 Jul 09.
Article in English | MEDLINE | ID: mdl-21705068

ABSTRACT

BACKGROUND: Lifestyle changes soon after diagnosis might improve outcomes in patients with type 2 diabetes mellitus, but no large trials have compared interventions. We investigated the effects of diet and physical activity on blood pressure and glucose concentrations. METHODS: We did a randomised, controlled trial in southwest England in adults aged 30-80 years in whom type 2 diabetes had been diagnosed 5-8 months previously. Participants were assigned usual care (initial dietary consultation and follow-up every 6 months; control group), an intensive diet intervention (dietary consultation every 3 months with monthly nurse support), or the latter plus a pedometer-based activity programme, in a 2:5:5 ratio. The primary endpoint was improvement in glycated haemoglobin A(1c)(HbA(1c)) concentration and blood pressure at 6 months. Analysis was done by intention to treat. This study is registered, number ISRCTN92162869. FINDINGS: Of 593 eligible individuals, 99 were assigned usual care, 248 the diet regimen, and 246 diet plus activity. Outcome data were available for 587 (99%) and 579 (98%) participants at 6 and 12 months, respectively. At 6 months, glycaemic control had worsened in the control group (mean baseline HbA(1c) percentage 6·72, SD 1·02, and at 6 months 6·86, 1·02) but improved in the diet group (baseline-adjusted difference in percentage of HbA(1c) -0·28%, 95% CI -0·46 to -0·10; p=0·005) and diet plus activity group (-0·33%, -0·51 to -0·14; p<0·001). These differences persisted to 12 months, despite less use of diabetes drugs. Improvements were also seen in bodyweight and insulin resistance between the intervention and control groups. Blood pressure was similar in all groups. INTERPRETATION: An intensive diet intervention soon after diagnosis can improve glycaemic control. The addition of an activity intervention conferred no additional benefit. FUNDING: Diabetes UK and the UK Department of Health.


Subject(s)
Diabetes Mellitus, Type 2/therapy , Adult , Aged , Aged, 80 and over , Combined Modality Therapy , Diabetes Mellitus, Type 2/diet therapy , Exercise Therapy , Female , Health Behavior , Humans , Intention to Treat Analysis , Life Style , Male , Middle Aged , Weight Loss
11.
Health Place ; 17(2): 633-40, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21292536

ABSTRACT

The benefits of regular physical activity for older adults are now well-established but this group remain the least active sector of the population. In this paper, the association between levels of neighbourhood deprivation and physical activity was assessed. A sample of 125 males with a mean age of 77.5 (±5.6) years, and 115 females with a mean age of age 78.6 (±8.6) underwent 7-day accelerometry, a physical performance battery, and completed a daily journeys log. Univariate associations between physical activity parameters and level of deprivation of neighbourhood were extinguished in regression models controlling for age, gender, and level of educational attainment. Age, gender, educational attainment, body mass index, physical function, and frequency of journeys from the home explained between 50% and 54% of variance in activity parameters. These results suggest the importance of strategies to help older adults maintain physical function, healthy weight, and remain active in their communities.


Subject(s)
Physical Fitness , Poverty Areas , Activities of Daily Living , Aged , Analysis of Variance , Educational Status , England , Female , Housing , Humans , Least-Squares Analysis , Male , Monitoring, Physiologic/instrumentation , Residence Characteristics
13.
Scand J Med Sci Sports ; 19(3): 406-11, 2009 Jun.
Article in English | MEDLINE | ID: mdl-18492054

ABSTRACT

In many Western countries, there are concerns about declining levels of physical activity in school-aged children. Active transport is one way to increase physical activity in children, but few studies have evaluated whether active transport in school-aged children and adolescents has beneficial effects on fitness and, if so, whether different modes of transport affect different aspects of fitness. In this study, we examined the association of active transport with different aspects of fitness in a representative Danish sample of 545 boys and 704 girls, 15-19 years of age. Physical fitness was assessed through a number of field tests, including a maximal cycle test, dynamic and static strength in different muscle groups, muscle endurance, flexibility and agility. Transport to school was reported as the mode of transport. Almost two-thirds of the population cycled to school. Cyclists had higher aerobic power than both walkers and passive travelers (4.6-5.9%). Isometric muscle endurance (10-16%), dynamic muscle endurance in the abdominal muscles (10%) and flexibility (6%) were also higher in cyclists compared with walkers and passive travelers. Mode of travel was not related to leisure-time sports participation. Our findings suggest that commuter bicycling may be a way to improve health in adolescents.


Subject(s)
Physical Fitness/physiology , Transportation/methods , Adolescent , Denmark , Exercise Test , Female , Humans , Male , Muscle Strength/physiology , Oxygen Consumption/physiology , Physical Endurance/physiology , Pliability/physiology , Young Adult
14.
Arch Dis Child ; 91(2): 175-6, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16428366

ABSTRACT

Questionnaire surveys suggest physical activity levels in children are low, particularly among children from deprived areas. Using accelerometers, it was found that children from a deprived inner city school were active at recommended levels and had similar levels of activity to children in other studies from more affluent populations. However, this finding was dependent on the threshold used to define moderate activity.


Subject(s)
Motor Activity , Schools/statistics & numerical data , Urban Health/statistics & numerical data , Child , Cross-Sectional Studies , England , Exercise , Female , Health Behavior , Humans , Male , Poverty Areas
15.
Int J Obes (Lond) ; 29(9): 1070-6, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15917845

ABSTRACT

OBJECTIVE: To determine the levels and patterns of physical activity in a sample of obese (> or =99th percentile body mass index (BMI)) and nonobese (<99th percentile BMI) children. DESIGN: Cross-sectional study. SETTING: Children were recruited from schools in Bristol and from the childhood obesity clinic, Bristol Royal Hospital for Children. Children were instructed in the use of the accelerometer either while at school or in the clinic, and wore the instrument while carrying out their normal daily activities for 7 days. PARTICIPANTS: A total of 133 children (mean age 10.5+/-0.8 y). In all 11 (16.9%) of the 65 girls and 14 (20.6%) of the 68 boys were classified as obese (above the 99th percentile for BMI and corresponding to projected adult BMI of 30). MAIN OUTCOME MEASURES: Objectively measured physical activity volume, intensity and pattern. RESULTS: Obese children were significantly less physically active overall than their nonobese counterparts (31,844+/-13,200 vs 41,844+/-10,430 counts/h; 95% confidence interval 4407 to 15592; P=0.001). Similarly the obese children spent less time in physical activity of moderate or greater intensity than the nonobese children (9.9+/-3.9 vs 12.9+/-4.2 min/h; 95% confidence interval 1.15 to 4.80; P=0.002). Hourly patterns of activity indicated a tendency in obese children to be less active than nonobese children at times when activity was more likely to be determined by free choice, particularly outside of school time. CONCLUSIONS: Obese children demonstrated patterns of physical activity that may have contributed to and are likely to sustain their obesity. Minute-by-minute accelerometry is a valuable tool to investigate physical activity patterns in obese children. It can identify periods when intervention to increase activity may be most appropriate and provide an evidence base for specific exercise prescription in primary and secondary care.


Subject(s)
Obesity/physiopathology , Physical Exertion/physiology , Body Mass Index , Child , Child Behavior , Choice Behavior , Circadian Rhythm/physiology , Cross-Sectional Studies , Female , Humans , Male , Monitoring, Ambulatory/instrumentation , Monitoring, Ambulatory/methods , Sex Factors
16.
J Comp Physiol B ; 174(3): 223-36, 2004 Apr.
Article in English | MEDLINE | ID: mdl-14712328

ABSTRACT

Haemoglobin function and respiratory status of sub-adult sharks, Heterodontus portusjacksoni was investigated for up to 1 week following transfer from 100% to either 75% or 50% seawater. Metabolic rates were unusually low and arterial-venous differences in blood O2 small. Haemodilution from osmotic inflow lowered haematocrit and reduced blood O2 content by up to 50%. There was no change in O2 consumption rate, blood O2 partial pressure, cardiac output, or the arterial-venous O2 content difference, and thus O2 delivery was maintained. Ventilation was acutely elevated but returned to normal within 24 h. The O2 delivery to the tissues was facilitated by decreased blood O2-affinity that could not be simply ascribed to changes in the osmolyte concentration. The Hb was unaffected by changes in intra-erythrocyte fluid urea or trimethylamine-N-oxide (TMAO) but was sensitive to changes in NaCl. The Bohr shifts in whole blood were low and there was little role for pH in modulating O2 transport. Venous Hb saturation remained close to 65%, at the steepest part of the in vivo O2 equilibrium curve, such that O2 unloading could be facilitated by small reductions in pressure without increasing cardiac or ventilatory work. H. portusjacksoni tolerated 50% seawater for at least 1 month, but there was little evidence of respiratory responses being adaptive which instead appeared to be consequential on changes in osmotic and ionic status.


Subject(s)
Acclimatization/physiology , Hemoglobins/physiology , Respiratory Physiological Phenomena , Sharks/physiology , Sodium Chloride/chemistry , Acclimatization/drug effects , Animals , Body Weight/physiology , Carbon Dioxide/metabolism , Cardiac Output/drug effects , Cardiac Output/physiology , Erythrocytes/chemistry , Erythrocytes/drug effects , Erythrocytes/metabolism , Hematocrit , Hemoglobins/analysis , Hemoglobins/metabolism , Hydrogen-Ion Concentration , Lactic Acid/blood , Methylamines/metabolism , Oxygen/blood , Oxygen/metabolism , Oxygen Consumption/drug effects , Oxygen Consumption/physiology , Partial Pressure , Pulmonary Ventilation/drug effects , Pulmonary Ventilation/physiology , Respiratory Mechanics/drug effects , Respiratory Mechanics/physiology , Respiratory Physiological Phenomena/drug effects , Seawater , Sodium Chloride/metabolism , Sodium Chloride/pharmacology , Urea/metabolism
17.
J Comp Physiol B ; 174(3): 211-22, 2004 Apr.
Article in English | MEDLINE | ID: mdl-14685759

ABSTRACT

In marine elasmobranch fish the consequences for CO2 and acid-base state of moving into low salinity water are not well described. Sub-adult Port Jackson sharks, Heterodontus portusjacksoni, occasionally enter brackish water and survive in 50% seawater (SW). The unidirectional Na efflux and content, plasma volume, glomerular filtration rate (GFR), body mass, as well as CO2 and acid-base state in H. portusjacksoni were investigated following transfer from 100% SW to 75% SW and then to 50% SW. A rapid water influx resulted in a doubling of the plasma volume within 24 h in sharks in 75% SW and an 11% increase in body weight. Osmotic water influx was only partially offset by a doubling of the GFR. There was a approximately 40% decrease in plasma [Na] through a transiently elevated Na clearance and haemodilution. The result was a decrease in the inward gradient for Na+ together with reductions of nearly 50% in CO2 and buffer capacity. The sharks remained hypo-natric to 50% SW by partially conforming to the decrease in external osmotic pressure and avoided the need for active Na+ uptake. The gradient for Na+ efflux would by extrapolation approach zero at approximately 27% SW which may of itself prove a lethal internal dilution. In sharks transferred to 75% SW, a small transient hypercapnia and a later temporary metabolic alkalosis were all largely explained through anaemia promoting loss of CO2 and buffer capacity. In sharks transferred to 50% SW the metabolic alkalosis persisted until the end of the 1-week trial. Within the erythrocytes, increased pH was consequent on the large decrease in haemoglobin content exhibited by the sharks, which caused a large reduction in intracellular buffer. In water as dilute as 50% SW there was no evidence of specific effects on the mechanisms of management of CO2 or H+ excretion but rather significant and indirect effects of the severe haemodilution.


Subject(s)
Acclimatization/physiology , Acid-Base Equilibrium/physiology , Carbon Dioxide/physiology , Seawater/chemistry , Sharks/physiology , Sodium Chloride/metabolism , Acclimatization/drug effects , Algorithms , Animals , Bicarbonates/metabolism , Body Weight/physiology , Carbon Dioxide/metabolism , Erythrocytes/chemistry , Erythrocytes/drug effects , Erythrocytes/metabolism , Glomerular Filtration Rate/drug effects , Glomerular Filtration Rate/physiology , Hydrogen-Ion Concentration , Osmotic Pressure , Partial Pressure , Plasma Volume/drug effects , Plasma Volume/physiology , Sodium Chloride/blood , Sodium Chloride/pharmacology , Water-Electrolyte Balance/physiology
18.
Prev Med ; 37(4): 363-7, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14507494

ABSTRACT

BACKGROUND: The aim of this study was to determine whether the number of participants with multiple coronary heart disease (CHD) risk factors exceeded the number expected from a random distribution. METHODS: A cross-sectional study of 1020 randomly selected boys and girls, 9 and 15 years old, was conducted. Risk factors were total cholesterol, HDL-cholesterol, triglyceride, serum insulin, and blood pressure. Physical fitness was assessed from a maximal cycle test and body fat from the sum of four skinfolds. Risk factors selected in the analysis were those related to the metabolic syndrome. RESULTS: More participants than expected had four or five CHD risk factors. Four risk factors were found in 3.03 (95% confidence interval (CI): 2.24-4.10) times as many participants as expected from a random distribution and five risk factors were found in 8.70 (95% CI: 4.35-17.4) times as many participants as expected. Fifty (5.4%) had four or five risk factors and in these individuals physical fitness was 1.2 standard deviation (SD) lower and body mass index (BMI) 1.6 SD higher than mean values for the population. CONCLUSION: Clustering of risk factors for the metabolic syndrome was found in children and adolescents. Low levels of physical fitness and raised BMI in these individuals indicate that lifestyle factors such as physical activity and diet may influence the development of these unhealthy risk profiles.


Subject(s)
Cardiovascular Diseases/etiology , Adolescent , Biomarkers , Blood Pressure , Cardiovascular Diseases/blood , Child , Cholesterol, HDL/blood , Denmark , Female , Humans , Insulin/blood , Male , Risk Assessment , Risk Factors , Triglycerides/blood
19.
Eur J Clin Nutr ; 54(12): 887-94, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11114687

ABSTRACT

OBJECTIVE: To determine the levels and patterns of daily physical activity in groups of normal-weight, overweight and obese adults using uniaxial minute-by-minute accelerometry. DESIGN: Cross-sectional study of physical activity levels over a 7 day period using accelerometers programmed to collect minute-by-minute data. SETTING: Participants were recruited from large companies in Bristol and Cardiff. All meetings took place on company premises. PARTICIPANTS: One-hundred and eight participants volunteered for the study. Eighty-four (36 males, 48 females; 38.6+/-9.3 y) (mean+/-s.d. ) met the inclusion criteria for accelerometer measurements and were included in analyses. RESULTS: No significant differences in physical activity were identified between normal-weight (BMI<25) and overweight (BMI 25-29.9) participants. Obese participants (BMI>30) were significantly less active than non-obese participants (BMI< or =30) during weekdays (279.1+/-77.5 vs. 391.3+/-139.4 counts min(-1); P<0.001), weekends (222.3+/-93.9 vs. 386.2+/-177.5 counts min(-1); P<0.001) and evenings (221.1+/-126.3 vs. 380.8+/-220.7 counts min(-1); P=0.002), but not at work (307.5+/-87.2 vs 398.7+/-163.3 counts min(-1); P=0.06). Differences in activity levels between obese and non-obese participants were greater in males than females. Hour-by-hour physical activity patterns demonstrated that obese participants were less active than the non-obese for almost every hour of the weekdays and the weekend. CONCLUSIONS: Although no differences in activity emerged between overweight and normal-weight individuals, obese participants were substantially less active than the non-obese, particularly when there was a free choice of activity or no activity. The difference in activity levels was particularly pronounced in males, and unless obese individuals are compensating by lower energy intake, these activity patterns will contribute to the maintenance of or increase in the degree of obesity. Minute-by-minute accelerometry is a valuable tool for the assessment of activity patterns and may be useful to highlight periods of inactivity for intervention design.


Subject(s)
Exercise , Leisure Activities , Monitoring, Ambulatory , Obesity/physiopathology , Adult , Body Weight , Cross-Sectional Studies , Female , Humans , Life Style , Male , Middle Aged , Monitoring, Ambulatory/instrumentation , Monitoring, Ambulatory/methods , Sex Factors , Time Factors
20.
Br J Gen Pract ; 50(461): 958-62, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11224966

ABSTRACT

BACKGROUND: Current guidelines for the management of hypertension recommend regular, moderate intensity aerobic exercise such as brisk walking as a means of blood pressure reduction. However, there is a lack of consistent evidence regarding the magnitude of blood pressure response to such a prescription. In particular, no well designed studies have investigated the efficacy of a programme of exercise meeting current guidelines. AIM: To investigate the effect of a six-week programme of moderate intensity exercise on daytime ambulatory blood pressure (10.00 am to 10.00 pm) among unmedicated, sedentary adults aged 25 years to 63 years with office blood pressure of 150 mmHg to 180 mmHg systolic and/or 91 mmHg to 110 mmHg diastolic. METHOD: Randomised controlled trial of participants carrying out 30 minutes of moderate intensity exercise (brisk walking or equivalent) five days per week for six weeks compared with controls who maintained existing levels of physical activity. RESULTS: Compliance with the exercise programme was high. The reduction in mean daytime ambulatory blood pressure between baseline and six-week follow-up was greater in the intervention group than in the control group for both systolic and diastolic blood pressure. However, this net hypotensive effect was not statistically significant (systolic = -3.4 mmHg, 95% CI = -7.4 to 0.6; diastolic = -2.8 mmHg, 95% CI = -5.8 to 0.2). Adjusting for baseline differences in mean ambulatory blood pressure in an analysis of covariance led to a reduction in the estimated magnitude of the effect (systolic = -1.9 mmHg, 95% CI = -5.4 to 1.7, P = 0.31; diastolic = -2.2 mmHg, 95% CI = -4.9 to 0.5, P = 0.11). CONCLUSION: Despite high compliance with the exercise programme, the magnitude of the hypotensive effect of moderate intensity exercise was not as great as that found in studies of higher intensity exercise among hypertensives. Expectations of general practitioners and patients that a programme of moderate intensity exercise will lead to a clinically important reduction in the individual's blood pressure are unlikely to be realised.


Subject(s)
Blood Pressure/physiology , Exercise Therapy/methods , Hypertension/prevention & control , Adult , Energy Metabolism/physiology , Female , Humans , Hypertension/physiopathology , Male , Middle Aged , Treatment Outcome
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