Functional Balance, Aerobic Capacity and Fatigue in Middle-Aged Diabetic Women: A Comparative Study

Introduction

Diabetes mellitus is a long-standing metabolic condition marked by elevated blood sugar levels, which over time can result in damage to vital organs such as the heart, kidneys, eyes, blood vessels, and nerves. Among its types, Type II diabetes is the most widespread, primarily affecting adults and developing due to insufficient insulin production or reduced sensitivity to insulin. A significant proportion of global diabetes cases are reported from low and middle-income nations. The condition is responsible for approximately 1.6 million deaths each year, and its global prevalence, including in India, continues to rise. Beyond its physiological effects, diabetes significantly disrupts individuals’ overall quality of life physically, psychologically, emotionally, and socially. One of the most common complaints among diabetic individuals is persistent fatigue, which may interfere with daily functioning and occupational engagement.^1-3

Type II diabetes mellitus poses particular challenges for middle-aged and older adults due to its association with increased fall risk and physical disability. Postural instability and impaired balance are frequently observed, even during basic tasks such as quiet standing, suggesting a heightened fall risk.^4-6 Individuals with diabetes may experience difficulties with maintaining balance during everyday movements, and studies report that they are up to five times more likely to fall than non-diabetics. These falls can contribute to reduced mobility, social withdrawal, institutionalization, and increased mortality. In clinical management, it is essential to consider both physiological factors such as muscle strength and proprioception and behavioral factors like fear of falling. According to Timar et al., balance disturbances in individuals with Type II diabetes are linked to deficits in sensory input related to movement, poor motor coordination, and autonomic dysfunction, including orthostatic hypotension.⁷

Aerobic capacity reflects the efficiency with which the cardiopulmonary system delivers oxygen to the muscles during sustained physical activity. It serves as a marker of cardiovascular health and endurance performance. Physical inactivity and reduced aerobic capacity are independently linked to poor outcomes in Type II diabetes.^8,9 Studies have demonstrated that individuals with Type II diabetes tend to have lower peak oxygen uptake (VO₂ peak) compared to healthy counterparts, and this reduction is a strong predictor of cardiovascular mortality.¹⁰

Fatigue, characterized by a persistent sense of tiredness, low energy, and reduced motivation, often interferes with daily functioning. In clinical settings, it is important to accurately identify the cause of fatigue to prevent worsening morbidity.^11,12,13 This symptom is frequently reported by individuals with Type II diabetes, sometimes even as an early sign of the disease. Although fatigue can result from various health conditions, it is particularly common in diabetic patients, with some studies suggesting that women may be more affected than men.^14-16 Despite this, there is limited literature focusing specifically on fatigue in middle-aged women with Type II diabetes.^17,18

Given the increased fear of falling among individuals with diabetes, it is plausible that balance control may be compromised in this population.¹⁹ Additionally, physical activity tends to decline in adulthood and stabilizes at low levels among middle-aged women. This reduction in physical activity is associated with muscle mass loss and may contribute to impaired balance.²⁰ Few studies have examined the relationship between functional balance, aerobic capacity, and fatigue in middle-aged women with diabetes. Therefore, this study aimed to assess and compare these parameters in middle-aged diabetic women and age-matched healthy controls.

Materials and Methods 

This comparative study was conducted over a period of six months, from March 2020 to August 2020. Following institutional approval, women aged 30 to 50 years with a physician-confirmed diagnosis of Type II diabetes mellitus for more than five years were screened based on predefined inclusion and exclusion criteria. Participant recruitment was carried out at a tertiary care hospital in Southern India.

Exclusion criteria included individuals with acute lower limb pain or inflammation restricting walking or exercise, total blindness, lumbosacral radiculopathy, partial or complete lower limb amputation, and those presenting with clinical signs of diabetic microvascular or macrovascular complications. Participants with any medical condition that would contraindicate participation in an exercise protocol were also excluded.

A total of 24 participants were included in the study. Data were collected on three key parameters: balance, aerobic capacity, and fatigue. These outcomes were then compared between the diabetic group and an age-matched group of healthy female participants. Ethical clearance for the study was obtained from the Institutional Ethics Committee prior to data collection.

Procedure

Women diagnosed with Type II diabetes mellitus, within the middle-aged category, were identified through medical records from a tertiary care hospital. Eligible participants were contacted, and those who expressed willingness to participate received a detailed explanation of the study protocol. Informed written consent was obtained from all subjects prior to data collection.

An age-matched control group was selected from the hospital staff. These individuals met the same inclusion and exclusion criteria, except for the absence of a diabetes diagnosis. All participants underwent an initial screening, during which demographic details were recorded.

Following the screening, each participant was assessed using three outcome measures: the Y-Balance Test to evaluate dynamic balance, the Rockport One-Mile Walk Test to assess aerobic capacity, and the Fatigue Assessment Scale (FAS) to measure fatigue levels. Both diabetic and non-diabetic participants completed the same assessment protocol under standardized conditions.

Balance

Dynamic balance was assessed using the Y-Balance Test (YBT), a reliable and time-efficient tool derived from the Star Excursion Balance Test (SEBT). The test requires the participant to stand on one leg while reaching as far as possible with the opposite leg in three specific directions: anterior, posterolateral, and posteromedial. This approach evaluates dynamic stability, strength, and postural control across multiple planes. The YBT simplifies the original eight-direction SEBT protocol while retaining its ability to assess asymmetrical balance and limits of stability.²¹ 

Aerobic capacity

The Rockport One-Mile Walk Test was employed to estimate the participants’ aerobic capacity by assessing their maximal oxygen uptake (VO₂ max). This submaximal exercise test evaluates the volume of oxygen the body can utilize during exertion, expressed in milliliters per kilogram of body weight per minute (mL/kg/min). VO₂ max was recorded as the peak value obtained upon completion of the walking assessment. Prior to testing, participants were instructed to wear loose-fitting clothing and appropriate footwear to ensure comfort and safety during the procedure.²² 

Fatigue

Fatigue levels were measured using the Fatigue Assessment Scale (FAS), a 10-item questionnaire designed to evaluate symptoms of chronic fatigue. Fatigue is a common and often disabling symptom reported across numerous health conditions. It is typically characterized by a persistent sense of tiredness, reduced motivation, and a reluctance to continue current activities. The FAS is widely used for monitoring fatigue Wover time and across clinical populations. The scale has demonstrated strong internal consistency, with a reported Cronbach’s alpha of 0.90.²³

Data Analysis

Statistical analysis of the data was done using the software SPSS 23.0. Descriptive statistics including median and range were calculated and summarized. Comparison between outcome measures in diabetes mellitus group and control group were done using Mann-Whitney U test as two outcomes were nominal variables and one was ordinal variable. Level of significance was set at 5%, 95% confidence interval and 80% power.

Results

Participants in the diabetes mellitus and control groups were matched for age. Significant differences were observed between the two groups in all measured outcomes. Individuals with diabetes mellitus demonstrated reduced balance scores on both the right and left sides as measured by the Y-Balance Test, lower estimated VO₂ max values obtained from the Rockport One-Mile Walk Test, and higher fatigue levels based on the Fatigue Assessment Scale. These findings indicate impaired balance, diminished aerobic capacity, and increased fatigue among participants in the diabetes mellitus group compared to their healthy counterparts.

Discussion

This cross-sectional study aimed to compare functional balance, aerobic capacity, and fatigue levels between middle-aged women with Type II diabetes mellitus (duration >5 years) and age-matched non-diabetic controls within the age range of 30 to 50 years. The assessments included the Y-Balance Test for dynamic balance, the Rockport 1-Mile Walking Test for aerobic capacity, and the Fatigue Assessment Scale (FAS) for fatigue severity. The results indicated that diabetic participants exhibited significantly reduced functional balance and aerobic capacity, along with higher levels of fatigue compared to non-diabetic counterparts.

Fatigue is frequently reported among individuals with Type II diabetes and may serve as an early indicator of disease progression or complications. While fatigue is not exclusive to diabetes, its impact appears more pronounced in individuals with long-standing Type II diabetes. The chronic metabolic dysregulation associated with diabetes can lead to multisystem impairments, including neuropathic, musculoskeletal, and cardiovascular dysfunctions, which cumulatively contribute to fatigue and reduced physical performance.^11,7

Impairments in the sensory-motor systems involved in balance regulation such as proprioceptive, visual, and vestibular inputs are common in individuals with Type II diabetes. This may explain the significant deficits in dynamic balance observed in the diabetic group. These impairments are often exacerbated by poor glycemic control, longer disease duration, and aging. Studies have shown that poor balance increases the risk of falls and lower limb dysfunction among diabetic individuals, particularly women in middle age.^6,15,16

Aerobic capacity, typically measured as VO₂ max, is considered a critical indicator of cardiovascular health. It has been widely reported that individuals with Type II diabetes demonstrate lower VO₂ max values than non-diabetic individuals of the same age. Reduced aerobic capacity in this population may stem from vascular changes, diminished cardiac output, and decreased muscular efficiency.^8,12,14

Balance deterioration with age is also a concern in healthy populations. Previous research has indicated that even in women without diabetes, dynamic balance tends to decline from maturity into midlife. Therefore, the presence of diabetes may further accelerate this decline. In this context, the current findings align with earlier studies that suggest diabetic individuals are at a heightened risk for falls and reduced physical fitness.^6,15-17

The association between fatigue and diabetes has been highlighted in several studies. Fatigue affects approximately 60% of diabetic patients and is often associated with physical inactivity, poor sleep quality, depression, and other comorbidities. It has been linked to decreased ability to perform daily tasks, reduced cognitive function, and diminished quality of life. Fritschi et al. noted that fatigue in diabetic women may result from a combination of physiological, psychological, and lifestyle-related factors.^15,24-27

Additionally, a growing body of evidence suggests that subtle impairments in sensory integration, executive function, and neuromuscular coordination may explain the increased fall risk in diabetic populations. Falls in middle-aged and older adults with diabetes are associated with serious consequences, including reduced mobility, social withdrawal, and higher mortality.^28,29

The current study adds to the limited literature by focusing on middle-aged diabetic women, a population often underrepresented in research. Their health concerns are frequently overshadowed due to sociocultural roles and limited access to preventive care. The findings underscore the importance of early assessment and targeted intervention in this demographic to address balance, aerobic fitness, and fatigue.

Conclusion

The findings of this study indicate that middle-aged diabetic women show reduced functional balance and aerobic capacity, and increased fatigue levels compared to age-matched healthy individuals. Future research should consider evaluating the relationship between cognitive function, physical endurance, and executive processing in this population. Longitudinal studies with larger sample sizes and more advanced tools for assessing functional performance may offer further insights into the long-term impact of diabetes on women’s health during midlife.

Funding

The authors received no financial support for the research and/ or authorship of this article.

Ethical clearance

The study was approved by the Institutional Ethical Committee.

Conflict of interest

The authors declare no conflict of interest with respect to the conduct of this study.