The effectiveness of physical leisure time activities on glycaemic control in adult patients with diabetes type 2: A Systematic Review

Abstract

Review Question/Objective 

The objective of this systematic review is to synthesise the best available evidence on the effectiveness of physical leisure time activities on glycaemic control in adult patients with diabetes type 2.

The specific review question is:

What is the effectiveness of physical leisure time activities on glycaemic control in patients with diabetes type 2?

Background 

Type 2 diabetes results from the body's ineffective use of insulin. Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both.Type 2 diabetes was previously called non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes.¹ According to 2011 National Diabetes Fact Sheet¹, diabetes affected 25.8 million people of all ages of United States population during 2005-2008, include 18.8 million diagnosed people and seven million undiagnosed people. Among United States residents ages 65 years and older, 10.9 million, or 26.9 percent, had diabetes in 2010. Recent World Health Organization (WHO) calculations indicate diabetes kills more than one million people annually, almost 80% of which occur in low- and middle-income countries. Almost half of diabetes deaths occur in people aged under 70 years; 55% of diabetes deaths are in women. WHO projects that diabetes deaths will double between 2005 and 2030.²

Type 2 diabetes is associated with older age³, obesity^{4, 5}, family history of diabetes⁶, history of gestational diabetes⁷, impaired glucose metabolism⁸, physical inactivity⁹, and race¹⁰. It is a common outcome of uncontrolled blood sugar and over time leads to serious complications including hypertension¹¹, blindness¹², kidney damage¹³, lower-limb amputations¹⁴, heart disease¹⁵, and stroke¹⁶. Good glycaemic control is a major goal in the treatment of type 2 diabetes mellitus to prevent and delay those severe long-term complications.¹⁷ Physical activity is considered to be a substantial part of the treatment of type 2 diabetes mellitus, as well as diet and medication.^{18, 19} Physical activity is a common physiological stressor that causes perturbation to glucose homeostasis and energy needs.²⁰

Several studies have reported the effects of physical activity on improving insulin sensitivity^{21, 22}, cardio-respiratory fitness²³, glycaemic control²⁴, and psychosocial well-being.²⁵ The American Diabetes Association suggests that people with type 2 diabetes spend at least 150 minutes a week on moderate-intensity physical activity (50-70% of maximum heart rate), or at least 90 minutes a week on vigorous physical activity (>70% of maximum heart rate).²⁶ Recent studies also indicate that moderate-intensity aerobic physical activity could help type 2 diabetes patients to maintain ideal glycaemic control.^{27, 28} Boule et al ²⁹ found physical activity training could reduce haemoglobin A₁c (HbA₁c) (control group vs. exercise group: 8.31% vs. 7.65%) by 0.66%. This is close to the effect of intense glucose-lowering pharmacological treatment found in the United Kingdom Prospective Diabetes Study.³⁰ A 1% absolute decrease in the HbA₁c value is associated with a 15% to 20% decrease in major cardiovascular events ³¹ and a 37% reduction in microvascular complications.³²

According to Zhao, Ford, Chaoyang's report (2011), only 25-42% of older adults with diabetes mellitus met recommendations for total physical activity based on the 2007 American Diabetes Association and 2008 Department of Health and Human Services guidelines.³³ Various barriers to regular physical activity had been described, such as health problems, lack of time or energy, no exercise partner, lack of family support, and motivation and working time.^{34, 35} An active lifestyle does not require complex exercise programmes. Instead, regular daily physical activity is believed to enable individuals to reduce the risk of chronic diseases and may enhance their quality of life.³⁶ Recently, it has been thought that, instead of structured physical activity, lifestyle physical activity is a better alternative for diabetes patients. Moderate or vigorous lifestyle or leisure time physical activities included jogging, walking, gardening, tai chi chuan, and qigong (an ancient Chinese breathing exercise that combines aerobics, isometric and isotonic movements and meditation).^{37, 38} According to data from recent studies, moderate physical leisure time activities for at least 60 minutes every week can effectively improve glycaemic control in patients with diabetes type 2.^{39, 40}

Those measure indicators of glycaemic control including glycated hemoglobin A₁c (HbA₁c), fasting plasma glucose (FPG), and postprandial plasma glucose (PPG) were used to assess glycaemic control in diabetic patients.⁴¹ HbA₁c value reflects the mean plasma glucose concentration over two to three months.^42,43 Fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) reflect short-term plasma glucose change. Glycated haemoglobin is a form ofhaemoglobin that is measured primarily to identify the averageplasmaglucoseconcentration over prolonged periods of time. The fasting plasma glucose test measures fasting blood sugar levels and the postprandial plasma glucose test is often used to test the effectiveness of the body's carbohydrate metabolism and the ability to produce insulin. ^{44, 45}

In 2010, Psaltopoulou et al gathered current information from meta-analyses on dietary and lifestyle practices concerning reduction of risk to develop type 2 diabetes⁴⁶. In 2009, Thomas et al completed a systematic review in which fourteen randomised controlled trials involving a total of 377 participants comparing exercise against no exercise in type 2 diabetes were identified. Trials ranged from eight weeks to twelve months duration. Compared with the control, the exercise intervention significantly improved glycaemic control as indicated by a decrease in glycated haemoglobin levels of 0.6%⁴⁷. This systematic review will differ from these two previously published reviews in that it aims to explore the effectiveness of different kinds of moderate or vigorous physical leisure time activities in improving glycaemic control in patients with diabetes type 2. A search of MEDLINE, DARE database, CINAHL, the Cochrane Library of Systematic Reviews and Joanna Briggs Institute Library of Systematic Reviews found no existing reviews or review underway on this topic.

Inclusion criteria

Types of participants

This review will consider adults over 18 years old diagnosed with type 2 diabetes mellitus according to 2003 American Diabetes Association criteria. Patients receiving oral or insulin medicine treatment will be considered for inclusion, regardless of severity of diabetes or other treatment regimes, but patients who had recently undergone serious operations or who had myocardial infarction, stroke, severe liver or kidney diseases, or any illness limiting participation in the physical activity program, or who were participating in a physical exercise program at the same time will be excluded from the study.

Types of Interventions

Regular physical leisure time activities for people with type 2 diabetes are defined as at least 150 minutes of moderate-intensity physical activity (50-70% of maximum heart rate) per week, or at least 90 minutes of vigorous-intensity physical activity (>70% of maximum heart rate) per week.²⁶ Theminimum duration of the intervention will be at least two months. The review will include the following forms of moderate or vigorous leisure time activities:

(1) tai chi exercise

(2) walking

(3) swimming

(4) gardening

(5) gigong (an ancient Chinese breathing exercise that combines aerobics, isometric, and isotonic movements and meditation)

(6) jogging

(7) riding a bicycle

(8) dancing.

Types of outcomes

The outcome measures will include long-term and short-term glycaemic control indicators to reflect the patients' immediate and two to three months blood sugar changing condition. Therefore, haemoglobin A₁c (HbA₁c), fasting plasma glucose (FPG), and postprandial plasma glucose (PPG) indicators will be included in this study.

Types of Studies

The review will consider any randomised controlled trials (RCTs). In the absence of RCTs, quasi-experimental studies, cohort and case-control studies will be considered for inclusion. This review will exclude cross sectional surveys, descriptive correlation studies and case series.

Search Strategy

The search strategy will be limited to the date range of 1966 to August 2012. The search strategy aims to find both published and unpublished studies in English and Chinese languages. A three-step search strategy will be utilised in this review. An initial limited search of PubMed and CINAHL Plus with full text will be undertaken followed by an analysis of the text words contained in the title and abstract, and of the index terms used to describe articles. A second search using all identified keywords and index terms will then be undertaken (Appendix I). Thirdly, the reference list of all identified reports and articles will be searched for additional studies.

The databases to be searched will include:

CINAHL Plus with Full Text

Scopus

PubMed

Academic Search Complete

The Cochrane Library of Controlled Trials

DARE databases (Database of Abstracts of Reviews of Effectiveness)

Mednar

Conference Proceedings

Dissertation Abstracts International

Airiti Library (CEPS)

Search item and keywords to be used will be:

Population

type 2 diabetes, type II diabetes

non-insulin-dependent diabetes mellitus

adult-onset diabetes

Intervention

leisure time activity

tai chi exercise

walking

swimming

gardening

gigong

jogging

bicycle

dancing

Outcomes

haemoglobin A₁c (HbA₁c)

fasting plasma glucose (FPG)

postprandial plasma glucose (PPG)

Assessment of Methodological Quality

Quantitative papers selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review using the standardised critical appraisal instruments from the Joanna Briggs Institute-Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix II). Any disagreements that arise between the reviewers will be resolved through discussion with a third reviewer.

Data Collection

Quantitative data will be extracted from papers included in the review using standardised data extraction tools from the JBI-MAStARI (Appendix III). The data extracted will include specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives. Any disagreements that arise between the reviewers will be resolved through discussion with a third reviewer.

Data Synthesis

Where possible, quantitative research study results will be pooled in statistical meta-analysis using the JBI-MAStARI. All results will be subject to double data entry. Odds ratio (for categorical data) and weighted mean differences (for continuous data) and their 95% confidence intervals will be calculated for analysis. Heterogeneity will be assessed statistically using the standard Chi-square. Where statistical pooling is not possible, the findings will be presented in narrative form including tables and figures to aid in data presentation where appropriate.

Conflicts of Interest

There are no conflicts of interest.