Diabetes, a worldwide pandemic, continues to present huge health burdens for most countries (Albright et al., 2000). Diabetes is considered a major risk factor for cardiovascular disease development. In the United States alone, over 10 million diagnosed and 5 million undiagnosed diabetes cases have been estimated in the general population (Albright et al., 2000). However, a large portion of this disease burden falls upon the older adults and minority populations (Castaneda et al., 2002). In particular, aging, coupled with unbalanced diets and physical inactivity are some factors indicated to exacerbate the problem and/or induce insulin sensitivity reduction. Globally, appropriate care of diabetes is largely essential at the primary care, where individuals with type 2 diabetes are treated, and the best practice for disease management is vital for success. The rise in the prevalence of type 2 diabetes, with associated complications have called upon researchers (Albright et al., 2000; Castaneda et al., 2002; Conn et al., 2007; Estacio et al., 1998; Michishita, Shono, Kasahara, & Tsuruta, 2008) to increasingly investigate therapeutic measures proposed to enhance quality of life and improve health outcomes.
Despite various studies documenting metabolic and/or glycemic control importance as well as pharmacological advances in this area, diabetic adults often fail to reach the required metabolic control levels, and this is found to be correlated with increased risks of medical problems associated with type 2 diabetes mellitus (Conn et al., 2007). The great variety of T2D complications and the limited time required to solve these problems make it difficult for nurses to personalize care for patients, considering individual barriers and needs. It is even more difficult when one has to choose from the various and increasing number of new standardized medications which may be beneficial, but also pose detrimental effects and risks. This problem area of study is important to enhance evidence-based practice in nursing as it calls for non-pharmacologic interventions, such as exercise to be an effective T2D self-management modality. The present analysis is, therefore, conducted to integrate, review and synthesize research findings examining therapeutic modalities for type 2 diabetes.
Aside from type 2 diabetes, a chronic disease proved to be among the leading causes of mortality and morbidity in the adult population worldwide, other concepts studied in literature are therapeutic measures likely to improve the disease outcomes (Albright et al., 2000; Castaneda et al., 2002; Conn et al., 2007). In this regard, exercise, described as the physical activity required to lower microvascular and macrovascular complications specific for diabetes is the emerging theme. Glycemic and/or metabolic control are determined by literature as the changes and outcomes in glucose tolerance, which show the role of physical activity on metabolic reactions in individuals with type 2 diabetes (Albright et al., 2000; Castaneda et al., 2002; Conn et al., 2007; Estacio et al., 1998). Maximal oxygen consumption is also a concept studied to reflect individual’s oxygen endurance capacity following prolonged exercise. The current scholarly works have explored the impact of behavior-change interventions on type 2 diabetes control and related risks.
The emerging concepts in the 5 studies include the effect of exercise on type 2 diabetes with regards to metabolic and glycemic control and/or oxygen consumption levels of individuals with T2D. From the articles, there is accumulating findings that cardiovascular disease is a resulting effect and a leading cause of mortality and morbidity in diabetic patients, but regular moderate and high-intensity exercises are effective in T2D management. These physical activities are associated with significantly improved glycemic and metabolic control, but such improvement may be affected by increased years of diabetes or insulin insensitivity. The rationale is that individuals with greater diabetic complications levels often have lower peak oxygen consumption (Estacio et al., 1998), which affects exercise capacity. Nonetheless, acute physical activity bouts can favorably change insulin resistance and abnormal blood glucose.
What was found similar in the studies is that frequent physical activities are beneficial in the management of type 2 diabetes; appropriate physical activities enhance glycemic control and increase insulin sensitivity. However, exercise capacity of the diabetic individual is important (Estacio et al., 1998). The diminished exercise performance due to diabetic macrovascular complications has negative implications for the ability of T2D individual to perform normal activities, which may augment cardiac morbidity and mortality risks. In line with the results, Castaneda et al. (2002) in their article validated that resistance training enhanced metabolic and glycemic control significantly, increased the fat-free mass, led to reduction in systolic pressure of the blood as well as abdominal adiposity, and concurrently reduced the medication requirements for diabetes. Therefore, subjects undergoing resistance training are more likely to reduce many of T2D-related abnormalities associated with the metabolic syndrome, including glucose intolerance, hypertension, and hypertriglyceridemia. Similarly, other researchers (Michishita et al., 2008; Albright et al., 2000) have found regular physical activity to have glucose-lowering effects and promote insulin sensitivity. According to Michishita et al. (2008), such improvements in insulinogenic index suggest better beta cell functioning after exercise therapy. Most importantly, all studies showed an adverse effect of less-favorable glycemic status on mortality; increased fitness was shown to promote glycemic control and metabolic outcomes (Conn et al., 2007), and reduce mortality risks associated with hyperglycemia.
However, there were mixed findings in literature on how exercise would be an effective modality in the management of type 2 diabetes, especially following diagnosis; hence the association between the capacity to exercise and cardiovascular disease. Some authors (Albright et al., 2000; Estacio et al., 1998) pointed out that certain microvascular and macrovascular complications associated with T2D impair exercise capacity. The rationale is that those with type 2 diabetes can adapt less to physical training as they have low maximal oxygen uptake (Estacio et al., 1998), yet modest increases in maximum oxygen consumption is essential in major reductions in cardiovascular risks and mortality rates (Albright et al., 2000). Therefore, findings by Estacio et al. (1998) in the NIDDM population without a coronary artery disease pointed to a possible connection between microvascular complications and the capacity to exercise.
While some authors (Castaneda et al., 2002) emphasized high-intensity, progressive resistance training to be effective in improving glycemic control and reducing defects associated with metabolic syndrome, Michishita et al. (2007) found the insulinogenic index in T2D patients to have improved even after a low intensity exercise therapy. Other researchers identified the combination of exercise and medical nutrition therapy as essential for the initial T2D treatment to the extent even when drug therapy is required, such measures of weight loss/maintenance are necessary for maintaining drug therapy efficacy (Albright et al., 2000). As indicated by Albright et al. (2000), while a low-intensity level exercise is adequate to aid metabolic changes, in some patients it may fail to meet the required minimum threshold of exercise capacity for improving cardiorespiratory endurance.
The current studies, collectively, were designed to investigate diverse interventions for improving self-management behaviors in T2D individuals, including increasing physical activity. Overall, as far as cardiac benefits are concerned, the data from these studies support the efficacy of non-pharmacological interventions to increase physical activity with or without emphasis on other self-care improvements. Although recommendations to commence exercise may not be appropriate for some populations with diabetic complications (Albright et al., 2000; Estacio et al., 1998), the most promising of the current studies, however, is the potential well-being and health gains of exercise therapy as outlined in the research. Most of the studies (Castaneda et al., 2002; Conn et al., 2007; Estacio et al., 1998) incorporated controlled experiments to test variations in the components and delivery of interventions. Such studies advance our understanding of appropriate strategies for assessing and enhancing cardiac functioning in adults with type 2 diabetes.
However, few limitations exist in the current studies. Some, by design, control subjects would receive standard care only, thereby lacking the same contact period as exercisers (Castaneda et al., 2002). These researchers also ignored the observed chest pains of participants during training, yet this underscores the importance of proper medical screening, prescription of the exercise, and supervision prior to implementing an exercise program. Consequently, questions regarding the feasibility of employing exercise as the treatment for type 2 diabetes present a number of potential pitfalls in the current type of studies. The 5 studies synthesized and/or used a small/large number of male/female subjects of the total samples used, posing unclear cardiovascular outcomes on whether women or men improve their behaviors less than their counterparts. On one hand, the 5 studies benefit from a cohort of motivated subjects, who are particularly interested in their health and will most likely engage in follow-up. However, in the real world, individuals with diabetes may lack the motivation, and if the non-pharmacological intervention is interrupted, efficacy results from exercise programs are difficult to achieve. In this regard, the current studies suffer from verifiability issues due to limitations emanating from lack of tools to assess adherence to the interventions, reproducibility, and fidelity.
With regards to the evaluation criteria of the 5 studies, it is important to note that the problem, purpose, question and/or hypothesis development of the current studies have been identified. These studies (Castaneda et al., 2002; Conn et al., 2007; Estacio et al., 1998) have clearly stated their purposes, problem, question and/or hypothesis development, and are congruent with the information articulated in the literature or references used. However, some descriptive studies (Albright et al., 2000) have not specifically identified these items; some have basically referred to them in the analysis (Michishita et al., 2008). The sample sizes used in these studies (if any) are adequate to produce generalizability of results and reduce the threat of sampling errors. The target populations have been clearly identified; the samples selected, and/or inclusion/exclusion criteria explained.
In this research, the concept of interest is whether exercise can change the risk of cardiovascular disease in patients with T2D when compared to the use of standard care within six months. From the research findings, there is enough evidence to show that exercise is an adjunct to standard care in individuals with type 2 diabetes (Castaneda et al., 2002), and is more effective than pharmacological therapies as it can change the risk of cardiovascular disease in this population. Consistent with this evidence, the studies that have explored the relationship between physical exercise and type 2 diabetes have discovered resistance training to be a possible modality for muscle endurance and strength, improved body flexibility and composition (Albright et al., 2000), increased glucose tolerance and sensitivity to insulin (Castaneda et al., 2002; Michishita et al., 2008), while decreasing risk factors for cardiovascular illnesses.
Why it would be emphasized that these studies focus on and support the fact that exercise, compared to standard care, change the risk of cardiovascular disease, is that most researchers incorporated quantified mechanisms comparing treatment and control groups. They either focused on interventions that would only emphasize exercise therapy or those targeting multiple health behaviors. These diverse studies (Albright et al., 2000; Castaneda et al., 2002; Conn et al., 2007; Estacio et al., 1998; Michishita et al., 2008) analyzing wide-ranging interventions to change diabetes behaviors presented important data to support our study concept.
In a large part, the intervention being recommended here is a non-pharmacological one, and the recommendations from the 5 studies are similar, though diverse. Of course, individuals with type 2 diabetes are prone to various cardiovascular risk factors such as dyslipidemia and hypertension (Albright et al., 2000). Therefore, behavioral interventions that incorporate physically active lifestyles are recommended as they help in the effective control of blood sugar levels and reduction of long-term complications of the disease. According to Albright et al. (2000), exercise, coupled with medical nutrition therapy is recommended for the initial treatment of T2D and lowering cardiovascular risk factors. Moderate weight loss has been found to aid sufficient metabolic goals, and regular exercise and nutrition therapy combined are even more effective in achieving quicker results unlike either alone of these strategies are used (Conn et al., 2007). For instance, exercise is recommended as it results in the preferential upper body fat mobilization. When exercise is combined with proper balanced diets, loss of visceral fats could be the resultant benefit leading to the reduction of obesity and substantial improvement in metabolic indices. In particular, abdominal obesity is deemed a major cardiovascular risk factor and aids the development of T2D (Albright et al., 2000). Exercise is, thus, a valuable adjunct modality along with changes in food intake when it comes to long-term management of weight. Besides, patients who indulge in regular exercises can observe better nutritional advice as physical activity enhances self-esteem and mood, and consequently contributes to improved control of food intake.
It is also stated that the psychosocial adjustments to T2D in later life may have significant consequences on the patient’s perceived stress, psychological health (Albright et al., 2000) and glucose control. Diabetic complications become more prevalent in individuals with long-standing T2D and who require psychosocial adjustments (Estacio et al., 1998). Therefore, given that the management of T2D is emotionally stressful, yet this stress can negatively affect glycemic control, unlike clinical interventions, regular physical activities can be a vital step in reducing stress while promoting psychological well-being and reducing cardiovascular risk factors. As explained by Michishita et al (2008), the major goal of type 2 diabetes treatment is to maintain and/or achieve near-normal – if not normal – levels of blood sugar. However, there is need for optimal lipid levels to be achieved, so as to prevent or delay microvascular or macrovascular complications. Aside from improving insulin sensitivity (Michishita et al., 2008), exercise, unlike many anti-diabetic medications, modifies lipid abnormalities and changes hypertensive levels to prevent cardiovascular diseases (Albright et al., 2000).
Nonetheless, exercise programs for adults with T2D and those without significant diabetic limitations or complications should demonstrate appropriate exercise endurance and resistance for ensuring cardiorespiratory fitness (Estacio et al., 1998), appropriate body composition, muscular endurance and strength (Albright et al., 2000). For that matter, the research has recommended well-rounded resistance training program to help in maintaining or increasing fat-free weight (Castaneda et al., 2002). In addition, appropriate intensity, frequency, modes and duration of the exercise program should be identified for adults with type 2 diabetes. To be effective in improving cardiovascular outcomes, and in turn secure successful results among the adults with type 2 diabetes, various interventions that are designed to encourage the adoption of exercise should be developed and be responsive to prevailing state of readiness of a given patient, and center on aiding individuals progress through the varied levels of behavioral change. Probably, for most exercise interventions, continuous monitoring and positive reinforcement are crucial, and this can be made possible through a variety of tools that deliver education, automated reminders, and counseling
There is no doubt Diabetes is considered a major risk factor for cardiovascular disease development in adults. With the review and appraisal of 5 studies exploring effective modalities for managing diabetes, exercise has been found to be an important regimen in the cardiovascular disease treatment in adults with T2D. As one of the potentially modifiable intervention, exercise programs are also an important component of fundamental prevention efforts. Lifelong exercise is largely the real target, but while some individuals commit to it, others do not. In particular, exercise has potential psychological and physical benefits in T2D patients, though these benefits are not often realized due to insufficient adherence to prescribed physical activity regimens (Albright et al., 2000). While we need a practical way to evaluate the exercise prescriptions for individuals with type 2 diabetes, provided there are no absolute contraindications or limitations, all adults with the disease should exercise. In this regard, our PICOT question is sustained