The effects of combined physical procedures on the functional status of patients with diabetic polyneuropathy

Introduction: Diabetic polyneuropathy is a common chronic complication in
 patients with diabetes mellitus. This study aimed to determine the
 importance of applied physical procedures on the functional status in
 diabetic polyneuropathy patients in comparison to the group of respondents
 with the applied alpha-lipoic acid. Materials and Methods: 60 subjects were
 divided into two groups: group A - diabetic polyneuropathy patient?s
 treatment with physical procedures; and group B - diabetic polyneuropathy
 patient?s treatment with alpha-lipoic acid. The study protocol implied that
 the study has lasted for three diagnostic and therapeutic cycles, each
 lasting for 16 days with the time between cycles of 6 weeks. Results:
 Manual muscle test, range of motion, Michigan Neuropathy Screening
 Instrument and Berg balance scale values showed statistically significant
 improvement at the end of testing the group A respondents, while in the
 group B respondents there was not any improvement shown. Conclusions: The
 application of the combined physical procedures shows clear benefit for
 improvement of muscle strength and mobility of the ankle joint in
 respondents with diabetic polyneuropathy.


Introduction
The common chronic complication in patients with diabetes mellitus (DM) (in more than 50% it occurs after 25 years' disease duration) is diabetic polyneuropathy (DPN) or distal sensorimotor polyneuropathy (DSP) [1]. There are approximately 600 000 people in Serbia suffering from DM or 8.2% of the population (out of which 95% of that population accounts for patients with type 2 diabetes), and 5.9% has diabetic neuropathy [2]. There is an increased risk of deformity, ulceration and amputation in these patients [3].
DSP leads to postural balance disorders and increased susceptibility to falls [4].
Deterioration of motor nerve fibers weakens the intensity of stimulation of the muscles which become hypotrophic. Injuries related to falls in these patients are 15 times more often compared to healthy respondents of the same age [5]. Also, muscle weakness and limitations of mobility in the ankles and the small joints of the foot occur over time. These disorders result in functional foot impairment, changing pressure points on the foot and the creation of ulceration [6]. Even 30% of diabetics have limited movements of small or large joints. Limited mobility in the ankle joint and metatarsophalangeal (MTPH) joint is caused by thickening and shortening of the ligaments and tendons, leading to increased plantar pressure of the forefoot [7]. Muscle weakness mainly dominates in the distal segments of the lower limb, thus threatening gait and other activities in daily life [8,9].
This study aimed to determine the importance of applied physical procedures on muscle strength and range of motion (ROM) in patients with DPN in comparison to the group of respondents with the applied alpha-lipoic acid (control group). It also aimed to determine if there is a statistically significant difference in the values of Michigan test for examining the neuropathy at the beginning and at the end of the study, between the group of respondents who underwent the combined physical therapy and the group of respondents who took alpha-lipoic acid.

Materials and Methods
This prospective, the study was done on 60 randomized patients, older than 18 years, at the Center for Physical Medicine and Rehabilitation, Clinical Center, Kragujevac, and was approved by the local Ethics Committee of the Clinical Center Kragujevac. This study is part of the previously published studies by Grbovic et al. [10][11].
Inclusion criteria were following: DPN with timeframe longer than 2 months with DPN signs and symptoms defined as pain, muscular weakness, paresthesia, hyperesthesia to anaesthesia and electromyoneurographic (EMNG) findings; without changes in antidiabetic treatment for at least of 6 months and who signed consent for participation in the study.
Patients who had following exclusion criteria were excluded from the study: deficiency of vitamin B12, moderate/severe use of alcohol, chronic kidney disease, dysfunction of the thyroid gland, any state of immunodeficiency, diseases of systemic connective tissues, severe damage of the liver, any kind of cerebrovascular ischemia, decompensation of heart failure, presence of acute coronary syndrome in the previous 6 months, uncontrolled high blood pressure (defined as values of systolic blood pressure higher than 160 mmHg and diastolic blood pressure higher than 80 mmHg), chemotherapy in the last decade, severe polytrauma or state after it, use of peripheral nerves damaging drugs (e.g. nitrofurantoin, paclitaxel, vincristine, cisplatin, indomethacin, emetine, streptomycin, dapsone, chloroquine, ethionamide, isoniazid, carbamazepine, phenytoin, hydralazine, metronidazole, amiodarone,); any sort of contraindication for the usage any of the arranged physical therapy agents (acute infectious disease, fever, pregnancy, malignancy, any acute vital organ failure, the presence of metal in body); or hypersensitivity to galactose, alpha-lipoic acid, Lapp lactose deficiency or glucosegalactose malabsorption.
The investigation was organized during 3 cycles of diagnostics and therapeutics, each lasting for 16 days with the timeframe between cycles of 6 ± 1 week (total study duration of six months).
Each subject was randomized into two groups of 30 patients each, with diabetes mellitus type 2 and DSMP, in light of clinical indications and signs, just as the parameters of EMNG discoveries. Utilizing computer randomization, every patient was arbitrarily assigned to one group (therapeutical arms): Group A or B.
Group A was treated with combined physical procedures that included pulsed electromagnetic field, exercise, stable galvanization and transcutaneous electrical nerve stimulation while group B was treated with alpha-lipoic acid as per conditions specified in the marketing license in Serbia. Detailed methods applied in these groups can be found in our previously published study [10].
On admission and after completion of the last diagnostical-therapeutical cycle (after Berg balance scale examined the balance in elderly people with vestibular disorders, assessing it through specific functional tasks. This is a valid instrument which is used to evaluate the efficiency of treatment, the quantitative description of the function in the clinical practice as well as the researches. The scale includes 14 functional tasks for assessing the balance in adults in clinical conditions with grades from 0 (the worst result) to difference is enough to show a change in function between the two measurements [15].
Distribution of all continuous variables was determined, using the Shapiro-Wilk test, the median value, minimum and maximum values, standard deviation (SD). Paired Ttest was used for comparison of the mean values of continuous variables within the tested groups with normal distribution or Wilcoxon's test of matched pairs. Independent T-test or the Mann-Whitney test for datasets without a normal distribution were used for comparison of differences between the groups. For comparison of the frequency (incidence) of categorical (dichotomous) variables, the χ2 test was used. P values less than 0.05 were considered as statistically significant. SPSS version 20.0 was used for statistical calculations. The statistics procedures were the same as in our previously published study [10][11].

Results
The baseline characteristics of respondents in group A and group B are given in Table 1. Since this study is part of previously published studies by Grbovic   days later. There were statistically significant reduced values of Michigan questionnaire for testing neuropathy in a group of respondents with the applied alpha-lipoic acid (p<0.01) [19]. In our study, we found that multiple physical procedures had a significant effect on MNSI score, however not for patients treated with alpha-lipoic acid. However, patients treated with alpha-lipoic acid had significantly lower MNSI score before starting with the treatment than patients treated with physical procedures.
Songet al. study indicated the importance of the application of exercise on balance improvement in patients with DPN. After the 8-week exercise implementation (60 min, 2x per week), a statistically significant improvement in balance was made (BBS, p <0.05) [20].
As in this study, our study showed that in patients treated with physical procedures a statistically significant improvement was made in postural equipoise and balance measured by Berg's balance scale (p=0.001). The group B respondents showed no statistically significant improvements.
Other study indicated the weakness of the muscles of the foot and limited mobility of the joints of the foot and ankle joint in patients with DPN, which later become risk factors for foot deformities and ulceration [21]. At the end of our study, the clear effects of  The statistical test used: a -Paired Sample T-test; b -Independent Sample T-test; * significance at p-value < 0.05 Table 3.

Manual muscle test of muscles of the lower extremities
Received on November 24, 2020.