Chronic Fall Risk Among Aged Individuals with Type 2 Diabetes
Approximately one-third of community-dwelling individuals over 65 years of age will experience a fall and one-half of these individuals will become chronic fallers.1-6 Chronic falling has been defined in the literature as falling two or more times within a 1-year period. Individuals who experience chronic or recurrent falling are more likely to sustain an injury during falling.7 In fact, 10% to 15% of these falls culminate in severe injury; fractures represent the greatest category of injury. The severity of complications associated with fall-related injury also has been shown to increase with age. A greater degree of disability and functional impairment is seen with elderly chronic fallers. Falls by the elderly account for the second leading cause of death in the aged population due to unintentional injury.
Numerous risk factors are associated with chronic falling.2-7 Braun8 identified three categories of fall-related risk factors: physical, psychological, and environmental. An additional category of risk factors is the presence of polypharmacy (three or more medications) and the resulting medication-induced side effects of each drug, as well as their respective interactions.
These chronic fall-related risk factors have been extensively studied in the geriatric population at large.2-7 However, chronic fall incidence for elderly individuals with type 2 diabetes mellitus has not been directly studied. A study that examined fall incidence and self-perception of fall-related injury potential of young individuals (mean age of 32.9 ± 2.5 years) with type 1 diabetes mellitus offers current data on fall risk for individuals with diabetes mellitus.9 Evaluation by multiple linear regression revealed that individuals with type 1 diabetes mellitus and a confirmed diagnosis of peripheral neuropathy were 15 times more likely to report an injury during gait activities as compared to their counterparts without neuropathy (P = 0.050). These individuals also reported feeling significantly less safe than their peers without neuropathy during standing and walking.
Fall-related injuries commonly sustained by individuals who participated in the above-described study by Cavanagh et al9 included fractures, sprained ankles, cuts, and bruises. Similar types of injuries have been detected in other epidemiological studies of individuals with diabetes.10-12 These studies have shown that individuals with diabetes have an increased prevalence of fractures.
For example, a study by Cundy et al12 showed an increased prevalence of metatarsal fractures in both males and females with diabetic neuropathy; results from another study demonstrated a greater prevalence of leg and foot fractures in females.11
Diabetic neuropathy is a common symptomatic complication of diabetes mellitus.13 Research has shown that 25% of individuals with a diagnosis of diabetes mellitus will develop peripheral neuropathy within 10 years of their original diagnosis; this percentage escalates to 50% by year 20 post-diagnosis. Likewise, the Rochester Diabetic Neuropathy Study14 showed that 60% to 65% of study participants developed some type of neuropathy, with 45% percent of these individuals exhibiting a distal-symmetric polyneuropathy.
Because of the high prevalence of peripheral neuropathy in individuals with diabetes mellitus15 and the increased prevalence of diabetes type 2 in the elderly population,16 chronic falling and its complications, including significant morbidity and mortality, may present a public health issue of epidemic proportions in the future. Currently, at least 16 million individuals in the United States are estimated to have diabetes mellitus. This number increases by approximately 800,000 each year.17 Diabetes care in the United States costs more than $137 billion per year, with approximately one-third of the Medicare budget directed at diabetes care. Additionally, chronic fall-related costs are estimated to be more than $10 billion annually and, as such, may represent an unrecognized significant healthcare cost for individuals with diabetes.18
In light of the elderly's increased risk of chronic falling and their greater susceptibility to developing type 2 diabetes mellitus16 and its complications, a case can be made for the need to further study the relationship of type 2 diabetes mellitus and chronic fall risk. Therefore, the purpose of this pilot study was threefold: to 1) examine the incidence of chronic falling in aged individuals with type 2 diabetes mellitus, 2) determine if a rural and urban elderly group of individuals with type 2 diabetes mellitus demonstrated a similar occurrence rate for chronic falling, and 3) determine whether similar risk factors for chronic falling existed in both rural and urban elderly individuals with type 2 diabetes mellitus.
Methods and Materials
This descriptive pilot study employed a convenience sample of two separate groups of aged individuals with type 2 diabetes mellitus from a southeastern state. One group of individuals (age range: 62 to 97 years) was recruited from a rural community center (RCC) program for seniors (N = 7) and a second group (age range: 57 to 83 years) was recruited from an urban day care center (UDCC) (N = 5). These centers were chosen because they were geographically separate and would provide independent groups of individuals that represented either a rural or urban setting from eastern North Carolina. Of the 12 participants, 11 were women; the study involved only one male participant. Findings for the one male patient were similar to the findings for the female members from his group. Informed consent was obtained from all participants who were screened for chronic fall potential at both the rural community center and the adult day care center. All procedures were conducted in accordance with the Institutional Review Board of East Carolina University. Identities of the study participants were protected by numerical coding of data and by grouping of data for analysis.
Six chronic fall-related risk factors were studied (see Table 1). Client histories/subjective evaluations were performed to collect data on history of falling within the past year, daily medication intake, and medical diagnoses. Physical screening was conducted at either the RCC or UDCC. Physical screening included balance and gait assessments along with assessment of lower extremity protective sensation.
Semmes-Weinstein monofilament testing was used to assess protective sensation status because it effectively quantifies the degree of neuropathy present in affected individuals.19 Lower extremity protective sensation was tested using a calibrated 5.07 Semmes-Weinstein monofilament over the following test sites: plantar surface of the great toe, first, third, and fifth metatarsal head, midfoot, heel and dorsal surface of midfoot. Before testing, the monofilament examination was explained to each individual and the procedure was demonstrated on their arms. During testing, a towel was placed over each participant's eyes. The participants also were asked to close their eyes. Individuals were instructed to respond verbally with a yes when they felt the monofilament against their skin. The monofilament test was performed with the 5.07 monofilament placed in contact with the skin on a perpendicular. Manual pressure was then applied to the monofilament until it buckled against the skin.
Gait and balance were assessed with the Tinetti Balance and Gait Tool.20 This performance-oriented mobility evaluation tool uses an ordinal scale for scoring that is completed by the tester/clinician and provides reliable measures and indicators of deteriorated stability and mobility and to indicate fall risk.20 This assessment includes sitting balance, sit-to-stand transfers, static and dynamic standing balance, and gait assessment. A critical threshold score of < 19/28 indicates that an individual is at extreme risk for falling. This threshold was used in the present study.
Relaxed gait velocity was calculated by a timed functional walk test performed over a 6-foot path. Research suggests that individuals with a slow or relaxed gait velocity of 45 to 53 cm/sec or less are at increased risk for falling.21,22 Therefore, this parameter was used in the present study to delineate individuals who may be at risk for falling due to their inability to avoid or react safely to events or obstacles in their environment. Research has indicated that aged individuals with any one of the six risk factors (history of falling, presence of multiple diagnoses, daily in-take of multiple medications, loss of lower extremity protective sensation, impaired balance, and slow walking speed) examined in this study place an individual at an increased risk for falling.2,4,20, 21
All of the individuals evaluated in this study were 57 years of age or older, with an age range of 57 to 83 years for individuals from the UDCC and 62 to 97 years from the RCC. Of the individuals evaluated, 100% were at risk for falling. Individuals were identified as being at risk for falling if any one of the six risk factors studied were present. Individuals from both groups presented with at least two fall-related risk factors. Additionally, both groups of individuals demonstrated a similar mean number of risks for chronic falling. Individuals from the UDCC exhibited a mean of 4.8 risk factors for chronic falling compared to 4.0 for individuals from the RCC.
No differences between clients in the two centers with respect to number of medications and comorbidities were found. In both groups, >50% of individuals reported a history of falling (see Table 2). The range of diagnoses for the individuals from the UDCC was three to nine compared to two to five for the individuals from the RCC (see Table 3). Diagnoses other than type 2 diabetes mellitus that were common in each group included hypertension (4/5 UDCC, 6/7 RCC), stroke/transient ischemic attack (TIA) (2/5 UDCC; 2/7 RCC), and arthritis/gout (2/5 UDCC; 2/7 RCC). Hypertension was the most common diagnosis of the three.
The range for daily drug intake in individuals from the UDCC was four to 11 drugs, compared to three to seven drugs for the RCC (see Table 4). All individuals in the study met the minimum criteria for fall risk of taking three or more medications daily; more than 80% of these individuals were found to be taking an antihypertensive agent. The other common medications taken by both groups included diabetic medications (insulin and/or oral hypoglycemic agents - all) and diuretics (3/5 UDCC; 2/7 RCC).
A higher percentage of individuals from the UDCC exhibited loss of protective sensation as compared to the RCC (see Table 2). Protective sensation loss as determined by the Semmes -Weinstein monofilament examination using the 5.07 monofilament was exhibited by 100% of the individuals from the UDCC. In comparison, only 67% of the individuals from the RCC demonstrated protective sensation loss via monofilament testing.
Similarly, a greater percentage of individuals from the UDCC were observed to have impaired balance and gait compared to individuals from the RCC (see Table 2). Forty percent of the individuals from the UDCC exhibited impaired balance and gait, compared to 29% of the individuals from the RCC. However, similar ratios of balance and gait impairment to loss of protective sensation were demonstrated by the two groups. The ratio was 0.40 for the UDCC as compared to 0.43 for the RCC.
Of the participants with type 2 diabetes in this study, 100% were found to be at high risk for chronic falling. Both groups demonstrated an increased risk for chronic falling with a mean of 4.8 versus 4.0 risk factors present in individuals from the UDCC compared to the RCC. These numbers are consistent with those from other studies in the aging population.2-4 Additionally, similar percentages of individuals from both groups had previous fall histories, medication intake, and number or comorbidities. This finding is of particular interest, considering that the individuals from the RCC had to travel from 1 to 2 hours for medical care and were located approximately 2.5 hours from a major medical center, compared to individuals from the UDCC who were within 30 minutes of a major teaching hospital.
A lower percentage of individuals from the RCC exhibited lower extremity protective sensation loss (67%) compared to the UDCC (100%). Similarly, a higher percentage of individuals from the UDCC (40%) compared to the RCC (29%) exhibited impaired balance and gait. Although the reason these two groups with similar mean ages, diagnoses, and numbers of comorbidities differed in their expression of protective sensation loss and impaired balance and gait is not known, the findings are consistent with previous studies that have found gait and postural abnormalities with diabetes mellitus.23-25 Gait deviations identified by these previous studies include a marked decrease in gait speed and stride length as well as an increased amount of time spent in double support (ie, bilateral stance or two-leg support).9,23 These gait changes result in a steadier and more conservative gait pattern that appears to require increased cognitive control. Research also has shown that individuals with diabetes mellitus and severe peripheral neuropathy exhibit a greater degree of body sway during standing.24,25 Both increased body sway and gait deviations are thought to be related to reduced proprioception in the lower extremities as a result of peripheral nerve damage.
The findings of a similar pattern or ratio of protective sensation loss to presence of impaired balance and gait in individuals with type 2 diabetes are consistent with the findings described above for individuals with type 1 diabetes.9 Individuals from the UDCC and RCC expressed a similar ratio of impaired balance and gait to protective sensation loss. Determining from this study whether this is a cause and effect relationship is difficult because impaired balance and gait may result from drug side effects, visual changes, systemic pathologies, and neural changes, among others. However, the presence of this similar pattern of loss in two independent groups suggests some type of relationship between protective sensation loss and development of impaired balance and gait. This ratio of impaired balance and gait to protective sensation loss indicates that approximately 40% of individuals with protective sensation loss may express impaired balance and gait or vice versa.
Other chronic fall-related risk factors detected in both populations included fall histories, presence of multiple medications, and comorbidities.2-7 Although research indicates that the presence of any one or combination of the above-listed risk factors place an elderly individual at risk for falling, the best predictor of a person's risk for additional falls appears to be a history of falling.6 In this study, similar percentages of individuals from both groups reported a previous fall (60% of UDCC and 57% of RCC participants), underscoring the similarity between these two independent groups.
Falling also has been shown to increase linearly as the number of disabilities that an individual has rises.26 All participants in this study were found to have two or more diagnoses, with the numbers ranging from three to nine for the UDCC and two to five for the RCC. Therefore, this data indicates that all of the individuals in this study are at risk for chronic falling. All of the participants in this study also met the minimum criteria for fall risk by taking three or more medications. Work by Granek et al27 has shown that individuals taking three or more medications have a greater risk of falling. Fall risk also has been shown to be increased in individuals taking antihypertensives. In the present study, more than 80% of the participants were taking antihypertensive medications.
A similar pattern for chronic fall-related risk factors occurred with the urban and rural groups of elderly individuals. Findings were also similar to those from previous studies that examined fall-related risk factors in community dwelling elderly.2-4 This study indicates that the aging individual with type 2 diabetes is at high risk for becoming a chronic faller. These individuals exhibited several fall-related risk factors other than the presence of impaired protective sensation. In fact, individuals with intact protective sensation also were at risk for falling. Taken together, these findings suggest the need for fall prevention education as a component of the risk prevention information given during diabetes education programs.
A limitation of this study is the small number of participants. However, similar findings were found across two independent groups, indicating that a larger study of chronic fall risk is warranted in individuals with type 2 diabetes mellitus.
Individuals with type 2 diabetes mellitus appear to be at significant risk for chronic falling and the injuries associated with falling. Individuals with type 2 diabetes also exhibit similar risk factors for chronic falling as those seen in the geriatric population at large. These findings indicate that fall prevention strategies should be considered for diabetes education programs and that educational interventions should occur early because people with and without protective sensation appear to be at risk for falling. This recommendation for early intervention is further supported by the findings of others who have demonstrated that individuals with a diagnosis of peripheral neuropathy show improved balance when treated in physical therapy with a focused exercise regimen.28 Individuals with type 2 diabetes mellitus, peripheral neuropathy, impaired balance and gait, and a history of falling may benefit from referral to physical therapy for balance and strength training. - OWM
The authors are indebted to the students that participated in the East Carolina University-Tillery Learn and Serve America Project and the Creative Living Center Diabetes Project. This project was supported in part by the East Carolina University-Tillery Learn and Serve America Project and by a grant to the Creative Living Center by Pitt County Memorial Hospital Foundation.