Prevalence of Musculoskeletal and Functional Abnormalities in Type 1 Diabetes Mellitus

Introduction

Diabetes mellitus (DM) represents a multifaceted metabolic disorder primarily affecting carbohydrate metabolism, wherein the deficiency of insulin, whether absolute (Type-1, T1DM) or relative (Type-2, T2DM), plays a pivotal role in disease progression.¹ T1DM is primarily caused by genetic factors, environmental factors, and disorder of the immune regulatory mechanism. The interaction of these three factors leads to the development of this autoimmune disease.

Globally, the prevalence of diabetes mellitus among individuals aged 20-79 years, as reported by the International Diabetes Federation in 2021, stands at approximately 10.5%, encompassing around 535 million individuals.² India constitutes the majority of pediatric cases of T1DM in the Southeast Asia region. As per the 6th edition of the International Diabetes Federation diabetes atlas, India reports three new cases of T1DM per 100,000 children aged 0-14 years.³ The prevalence of diabetes across India exhibits variability, with data indicating 17.93 cases per 100,000 children in Karnataka, 3.2 cases per 100,000 children in Chennai, and 10.2 cases per 100,000 children in Karnal (Haryana).^4,5

Nonetheless, T1DM remains widespread in the country. In recent years, there has been a notable rise in both the prevalence of diabetes mellitus and the life expectancy of affected patients, leading to a corresponding increase in the incidence of musculoskeletal (MSK) complications associated with diabetes, thereby impacting both the quality of life and health outcomes.

Numerous musculoskeletal conditions affecting the upper extremities have been linked to Type 1 diabetes, potentially resulting in painful and debilitating limitations.^6,7 Diabetic cheiroarthropathy manifests as thickened skin and restricted joint mobility in the hands and fingers, often leading to flexion contractures like Dupuytren’s contracture and conditions such as flexor tenosynovitis or trigger finger. Additionally, adhesive capsulitis of the shoulder is more prevalent among individuals with diabetes compared to those without, potentially sharing a similar underlying pathogenesis with other musculoskeletal disorders associated with the condition.^6,8 The buildup of advanced glycation end products (AGEs) within collagen has been suggested as the fundamental mechanism behind these conditions.⁹ Furthermore, Carpal tunnel syndrome has historically been linked with diabetes and is believed to be connected to both the glycation of connective tissues and diabetic neuropathy.

The primary aim of this study was to evaluate the prevalence of functional and structural musculoskeletal abnormalities in children and adolescents diagnosed with Type 1 Diabetes Mellitus (T1DM). Additionally, our objectives include investigating the correlation between diabetes duration, glycaemic control, and the occurrence of musculoskeletal abnormalities.

Material and Methods

A total of 107 patients, aged between 5 and 25 years, diagnosed with Type 1 Diabetes Mellitus (T1DM), were recruited from the KLES Diabetes Centre in Belagavi, India.

Data Collection

Using standardised questionnaires, information on age, sex, diabetes duration, and pain intensity in muscles and joints was collected.

Physical Assessment

The assessment comprised the following components:

Range of Movements (ROM)

A bilateral assessment of ROM was conducted in both upper and lower limbs.

Goniometric Measurements

Goniometric measurements were taken for passive ROM if joint restriction was observed.

Functional Activities and Limb Deformities

Evaluation of functional activities and identification of any limb deformities were performed.

The Disability of the Arm, Shoulder, and Hand (DASH) questionnaire is a self-reported tool designed to evaluate restrictions in daily activities caused by upper limb conditions. It encompasses various functional tasks such as grooming, dressing, household chores, and work related activities. The core component of the DASH comprises a 30-item scale focusing on disability and symptoms, reflecting the patient's health status over the preceding week.¹⁰ These items inquire about the level of difficulty experienced in various physical activities due to issues with the arm, shoulder, or hand (21 items), the severity of specific symptoms, including pain, activity-related pain, tingling, weakness, and stiffness (5 items), as well as the impact of the problem on social activities, work, sleep, and self-image (4 items). Each item provides five response options. Subsequently, scores from all items are aggregated to generate a scale score ranging from 0 (indicating no disability) to 100 (representing the most severe disability).

Objective Measurements

CHIPPAUX Index

Footprint analysis was utilized to calculate the CHIPPAUX index.

Weight-Bearing during Walking

An assessment of weight-bearing during walking was conducted.

Q Angle

The Q angle was measured to assess knee deformity.

Statistical Analysis

We used descriptive statistics to summarize numerical data. Categorical data (e.g., gender, presence of a specific foot abnormality) was described using frequencies and percentages. Fisher's exact test was employed to compare the proportions of patients between the two groups.

Results

The data on the prevalence of various structural abnormalities of the foot and toes in 107 patients with type 1 diabetes mellitus (DM) included in the study is tabulated in Table 1.

Most Common Abnormalities

Hallux Valgus (bunion) was the most prevalent abnormality, affecting 24 (44.44%) patients. Pes Planus (flat feet) was also relatively common, seen in 16 (29.60%) patients.

Less Frequent Abnormalities

Pes cavus (high arches), pes varus (inward-turned foot), pes valgus (outward-turned foot), claw toe, supra ductus, and hammer toe were observed in a smaller proportion of patients (less than 2% each). Hallux valgus and pes planus might be due to altered biomechanics of the foot caused by neuropathy or changes in gait patterns in diabetic patients.

Table 2 summarises the prevalence of structural knee abnormalities in patients with T1DM included in the study. Knee abnormalities were relatively uncommon in this group, with genu valgus (knock knees) affecting only four patients (4.28%) and genu varum (bow legs) affecting three patients (2.80%). A combined total of seven patients (7.49%) had some form of knee misalignment among the 107 studied. Diabetes is more likely to affect the feet due to neuropathy and circulatory issues and may have less impact on the knees compared to the feet.

The prevalence of structural abnormalities and complications in patients with T1DM included in the study is depicted in Table 3. Prayer sign was the most prevalent structural abnormality, affecting 27 patients (25.2%).

Spinal Abnormality

Relatively uncommon, seen in only three patients (2.80%).

Muscle Complications

Thenar and hypo thenar wasting was present in 13 patients (13.91%), and muscle pains were reported in 22 patients (20.56%). Diabetes affects nerves and blood flow, potentially leading to neuropathy, muscle wasting (wasting of the thenar and hypothenar muscles), and joint stiffness (reflected in the positive prayer sign). The functional abnormalities were detected by a decrease in range of movements leading to limitations in flexibility and mobility and was observed in 16 (14.95%) subjects in the present study.

Table 4 summarises the prevalence of various skin and nail problems observed in 107 patients with T1DM included in the study.

Foot Problems

Several conditions listed are related to the feet, including callus (10.7%), hyperkeratosis (8.56%), foot ulcers (4.28%), and open wounds. This is due to neuropathy, which leads to decreased sensation and impaired ability to feel pressure points. Poor circulation affects healing and increases the risk of infections.

Other Skin Problems

Blisters, Mycosis (fungal infection), and inflamed cuticles were observed in a smaller proportion of patients.

Nail Problems

Hyperconvex nails (curved upwards), fungal nails, and inflamed cuticles were noted in a limited number of cases.

Table 4 shows the distribution of DASH (Disabilities of the Arm, Shoulder, and Hand) scores in 107 patients with type I diabetes mellitus (DM) included in the study.

Most Common Range

The highest percentage of patients (42.99%) scored between 41- 60 on the DASH, indicating moderate functional limitations.

Lower and Higher Scores

A significant portion (20.56%) scored between 21-40 (indicating mild limitations), while a smaller proportion (13.08%) scored 0-20 (no to minimal limitations), and 21.49% scored between 61-80 (severe limitations). Only a small number (1.86%) scored in the highest range (81-100), indicating severe limitations. Diabetes can potentially affect the upper limbs through various mechanisms, such as nerve damage or complications like Carpal tunnel syndrome. The distribution of DASH scores suggests that many patients with type I diabetes experience some degree of functional limitations in their upper limbs.

Table 6 analyses the potential association between the duration of diabetes, HbA1c levels, and the presence of structural abnormalities in 107 patients with type 1 diabetes mellitus (DM) included in the study.

Duration of Diabetes

About 39.28% of patients with diabetes for 3-5 years showed abnormalities. This percentage increased to 47.45% for those with diabetes for 6-8 years and 75.00% for those with a history of diabetes for more than eight years.

HbA1c Levels

A similar trend was noted with HbA1c levels. The percentage of patients with abnormalities increased with higher HbA1c levels. Only 12.9% of patients with HbA1c between 7.0 and 8.0 (considered reasonable control) had abnormalities. This percentage rose to 57.89% for HbA1c of 8.1-9.0 and 89.47% for those with 9.1-10.0 HbA1c (considered poor control). These observations suggest a potential link between longer diabetes duration, poor glycaemic control (reflected by HbA1c), and an increased risk of developing structural abnormalities. Chronically high blood sugar levels associated with diabetes might contribute to nerve damage, circulatory problems, and other factors that can lead to structural changes in the body, including the feet and spine.

Discussion

The critical finding of this study was the high prevalence of structural foot abnormalities (50.46%) compared to knee abnormalities (7.49%). Hallux Valgus (bunion) was the most common foot abnormality (44.44%). Pes Planus (flat feet) was also relatively frequent (29.60%). Genu Valgus and Genu Varum abnormalities were not expected, but they were observed in 7.49% of cases. Thenar and hypothenar wasting and muscle pain were observed (13.91% and 20.56%, respectively). Spinal abnormalities in the form of spinal stenosis were found in 2.8% of the cases. Skin and nail problems due to neuropathy and circulatory issues included callus (10.7%), hyperkeratosis (8.56%), foot ulcer (4.28%), and open wounds (2.80%).

DASH Scores

A substantial portion of the patients (42.99%) scored between 41-60, indicating moderate limitations. Significant portions were scored in the mild (21-40) and severe (61-80) limitation ranges (20.56% and 21.49%, respectively). 75% of cases with a duration of diabetes > 8 years were found to have abnormalities. Similarly, those with HbA1c of >9 (89.47%) were found to have abnormalities.

Musculoskeletal abnormalities in children and adolescents with T1DM are a significant clinical concern because of their potential impact on mobility, quality of life, and long-term complications. Our study aimed to assess the prevalence of these abnormalities and investigate the possible correlations between diabetes duration and glycemic control. Our findings revealed a notable prevalence of musculoskeletal abnormalities in patients with T1DM. These abnormalities encompassed a spectrum of functional impairments, including reduced range of motion (ROM), joint restrictions, increased DASH scores, and limb deformities. The observed prevalence aligns with those of previous studies, indicating a consistent association between T1DM and musculoskeletal issues.¹¹

One of the critical objectives of our study was to explore the relationship between musculoskeletal abnormalities, diabetes duration, and glycaemic control. We found a significant association between longer diabetes duration and an increased prevalence of musculoskeletal impairments, suggesting the progressive nature of these complications over time. Moreover, poor glycaemic control is a potential risk factor for the development and exacerbation of musculoskeletal abnormalities. These findings underscore the importance of early intervention and optimal diabetes management to mitigate the impact of such complications.¹² Several comparative studies have corroborated our findings regarding the prevalence and correlates of musculoskeletal abnormalities in patients with T1DM. For instance, a study by Smith et al.¹³ demonstrated a higher prevalence of joint stiffness and reduced ROM in pediatric patients with T1DM than in age-matched controls. Similarly, Walter et al.¹⁴ reported a significant association between longer diabetes duration and an increased incidence of foot deformities and neuropathy in adolescents with T1DM. Identifying musculoskeletal abnormalities in individuals with T1DM warrants comprehensive clinical assessment and targeted management strategies. The early detection of these complications is crucial to prevent further deterioration and mitigate the risk of long-term disability. Multidisciplinary approaches, including physical therapy, orthotic interventions, and glycemic control optimization, are pivotal for addressing musculoskeletal issues and improving patient outcomes.¹⁵

Conclusion

Our study highlights the high prevalence of musculoskeletal abnormalities in children and adolescents with T1DM and underscores the importance of proactive screening and management strategies. Longitudinal monitoring of musculoskeletal health, along with rigorous glycaemic control, is essential to mitigate the burden of these complications and enhance the overall well-being of patients with T1DM.

Source of Support

None

Ethical Permission

Obtained

Conflict of Interest

None