Prevalence and risk factors for diabetes and diabetes-related amputations in American Indians in southern Arizona

Patterns and risk factors associated with index Lower Extremity Amputations (LEA) among Type 2 Diabetes Mellitus (T2DM) patients in Fiji

AIM

To describe patterns of index (first ever) Lower Extremity Amputations (LEA) and to determine factors associated with their occurrence amongst Type 2 Diabetes Mellitus (T2DM) patients in Fiji.

METHODS

This cross-sectional study was conducted that adheres to the STROBE check lists for observational research among T2DM patients who experienced index LEA at the Colonial War Memorial Hospital (CWMH) in Fiji between 2011 and 2015. Demographic and clinical variables were extracted from patient folders. Univariate and multivariate logistic regression were used to determine factors associated with Major LEA. A p-value < 0.05 was considered significant.

RESULTS

A total of 649 study participants were studied with the average age of index amputation was 58.4 years (±9.6 years, range 30-91 years). The average duration of T2DM was 9.5 ± 5.7 years. LEAs were more common amongst males (55%) and indigenous Fijians (71.8%). One-third of index LEA (33%) were major amputations. Factors associated with occurrence of Major LEA were poor Random Blood Sugar (RBS) levels (OR = 1.68, 95% CI: 1.01, 2.81), midfoot lesion (OR = 9.38 95% CI: 4.95, 19.52), septicaemia (OR = 2.42, 95% CI: 1.28, 4.57), low haemoglobin level (OR = 0.78 95% CI: 0.72, 0.86), and history of hypertension (OR = 0.58, 95% CI: 0.40, 0. 84).

CONCLUSIONS

Results indicate that diabetic patients with foot infections present late to tertiary level care. Our findings also show an urgent need to strengthen primary care interventions and surveillance of both diabetes and diabetic LEA.

Risk of lower limb amputation in a national prevalent cohort of patients with diabetes

AIMS/HYPOTHESIS

Lower limb amputation is a serious complication of diabetes mellitus. Understanding how amputation risk differs by population subgroups is crucial in terms of directing preventive strategies. In this study, we describe those factors that impact amputation risk in the entire prevalent diabetic population of New Zealand.

METHODS

A national prevalent cohort of 217,207 individuals with diabetes in 2010 were followed up until the end of 2013 for lower limb amputations, and 2014 for mortality. Inpatient hospitalisation data were used to define lower limb amputation using ICD-10 codes. Cox proportional hazards models were used to describe relative hazard of amputation over the follow-up period.

RESULTS

A total of 784 individuals (3.6 cases/1000 individuals) underwent a major (above-ankle) lower limb amputation during follow-up, while 1217 (5.6/1000) underwent a minor (below ankle) amputation. The risk of major and minor amputation was 39% and 77% greater for men than women, respectively (adjusted HR: major amputation 1.39, 95% CI 1.20, 1.61; minor amputation 1.77, 95% CI 1.56, 2.00). Indigenous Māori were at 65% greater risk of above-knee amputation compared with the European/Other diabetic population (HR 1.65, 95% CI 1.37, 1.97). Amputation risk increased with increasing comorbidity burden, and peripheral vascular disease conferred the greatest independent risk of all comorbid conditions. Prior minor amputation increased the risk of subsequent major amputation by tenfold (HR 10.04, 95% CI 7.83, 12.87), and increased the risk of another minor amputation by 20-fold (HR 21.39, 95% CI 17.89, 25.57). Death was common among the total cohort, but particularly among those who underwent amputation, with more than half of those who underwent a major amputation dying within 3 years of their procedure (57%).

CONCLUSIONS/INTERPRETATION

Using a large, well-defined, national prevalent cohort of people with diabetes, we found that being male, indigenous Māori, living in deprivation, having a high comorbidity burden and/or having a previous amputation were strongly associated with subsequent risk of lower limb amputation. The use of this prevalent cohort strengthens the value of our estimates in terms of applicability to the general population, and highlights the subgroups at greatest risk of lower limb amputation.

Clinical review: Prevalence and incidence of endocrine and metabolic disorders in the United States: a comprehensive review

CONTEXT

There has not been a comprehensive compilation of data regarding the epidemiology of all endocrine and metabolic disorders in the United States.

EVIDENCE ACQUISITION

We included 54 disorders with clinical and public health significance. We identified population-based studies that provided U.S. prevalence and/or incidence data by searching PubMed in December 2007 for English-language reports, hand-searching reference lists of six textbooks of endocrinology, obtaining additional resources from identified experts in each subspecialty, and searching epidemiological databases and web sites of relevant organizations. When available, we selected articles with data from 1998 or later. Otherwise, we selected the article with the most recent data, broadest geographical coverage, and most stratifications by sex, ethnicity, and/or age. Ultimately, we abstracted data from 70 articles and 40 cohorts.

EVIDENCE SYNTHESIS

Endocrine disorders with U.S. prevalence estimates of at least 5% in adults included diabetes mellitus, impaired fasting glucose, impaired glucose tolerance, obesity, metabolic syndrome, osteoporosis, osteopenia, mild-moderate hypovitaminosis D, erectile dysfunction, dyslipidemia, and thyroiditis. Erectile dysfunction and osteopenia/osteoporosis had the highest incidence in males and females, respectively. The least prevalent conditions, affecting less than 1% of the U.S. population, were diabetes mellitus in children and pituitary adenoma. Conditions with the lowest incidence were adrenocortical carcinoma, pheochromocytoma, and pituitary adenomas. Certain disorders, such as hyperparathyroidism and thyroid disorders, were more common in females. As expected, the prevalence of diabetes mellitus was highest among ethnic minorities. Sparse data were available on pituitary, adrenal, and gonadal disorders.

CONCLUSIONS

The current review shows high prevalence and incidence of common endocrine and metabolic disorders. Defining the epidemiology of these conditions will provide clues to risk factors and identify areas to allocate public health and research resources.

Global complication rates of type 2 diabetes in Indigenous peoples: A comprehensive review

INTRODUCTION AND OBJECTIVE

The world's Indigenous peoples are experiencing an unprecedented epidemic of type 2 diabetes [T2DM] but little has been published describing the complications burden. The objective of this paper was to conduct a systematic review of T2DM complications in Indigenous populations worldwide.

METHODS

A literature review was conducted using PubMed and EMBASE to examine available complications data. Country, Indigenous population, authors, publication year, total sample size, Indigenous sample size, age, methodology, and prevalence of nephropathy, end-stage renal disease, retinopathy, neuropathy, lower extremity amputations, cardiovascular disease, hospitalizations and mortality due to diabetes were recorded.

RESULTS

One-hundred and eleven studies were selected. Results revealed a disproportionate burden of disease complications among all Indigenous peoples regardless of their geographic location. Complication rates were seen to vary widely across Indigenous groups.

DISCUSSION

Gaps were found in the published literature on complications among Indigenous populations, especially those living in underdeveloped countries. These gaps may be in part due to the challenges caused by varying operational practices, research methodologies, and definitions of the term Indigenous, making documentation of rates among these peoples problematic. Comprehensive surveillance applying standardized definitions and methodologies is needed to design targeted prevention and disease management strategies for Indigenous peoples with T2DM.

Incidence of lower-extremity amputation in American Indians: the Strong Heart Study

OBJECTIVE

To define incidence and predictors of nontraumatic lower-extremity amputation (LEA) in a diverse cohort of American Indians with diabetes.

RESEARCH DESIGN AND METHODS

The Strong Heart Study is a study of cardiovascular disease and its risk factors in 13 American-Indian communities. Data on the presence/absence of amputations were collected at each of three serial examinations (1989-1992, 1993-1995, and 1997-1999) by direct examination of the lower extremity. The logistic regression model was used to quantify the relationship between risk of LEA and potential risk factors, including diabetes duration, HbA(1c), peripheral arterial disease, and renal function.

RESULTS

Of the 1,974 individuals with diabetes and without prevalent LEA at baseline, 87 (4.4%) experienced an LEA during 8 years of follow-up, and a total of 157 anatomical sites were amputated among these individuals. Amputation of toes was most common, followed by below-the-knee and above-the-knee amputations. Age-adjusted odds of LEA were higher among individuals with unfavorable combinations of risk factors, such as albuminuria and elevated HbA(1c). Multivariable modeling indicated that male sex, renal dysfunction, high ankle-brachial index, longer duration of diabetes, less than a high school education, increasing systolic blood pressure, and HbA(1c) predicted LEA risk.

CONCLUSIONS

The 8-year cumulative incidence of LEA in American Indians with diabetes is 4.4%, with marked differences in risk by sex, educational attainment, renal function, and glycemic control.

Relation of lower-extremity amputation to all-cause and cardiovascular disease mortality in American Indians: the Strong Heart Study

OBJECTIVE

To compare risk of all-cause and cardiovascular disease (CVD) mortality in people with a lower-extremity amputation (LEA) attributable to diabetes and people without an LEA.

RESEARCH DESIGN AND METHODS

The Strong Heart Study is a study of CVD and its risk factors in 13 American-Indian communities. LEA was ascertained at baseline by direct examination of the legs and feet. Mortality surveillance is complete through 2000.

RESULTS

Of 2,108 participants with diabetes at baseline, 134 participants (6.4%) had an LEA. Abnormal ankle-brachial index (53%), albuminuria (87%), and long diabetes duration (mean 19.8 years) were common among diabetic subjects with LEA. Mean diabetes duration among diabetic participants without LEA and in those with toe and below-the-knee amputations was 11.9, 18.6, and 21.1 years, respectively. During 8.7 (+/-2.9) years of follow-up, 102 of the participants with LEA (76%) died from all causes and 35 (26%) died from CVD. Of the 1,974 diabetic participants without LEA at baseline, 604 (31%) died from all causes and 206 (10%) died from CVD. The unadjusted hazard ratios (HRs) for all-cause and CVD mortality in diabetic participants with LEA compared with those without were 4.0 and 4.1, respectively. Adjusting for known and suspected confounders, LEA persisted as a predictor of all-cause (HR 2.2, 95% CI 1.7-2.9) and CVD mortality (HR 1.9, 95% CI 1.3-2.9). We observed a significant interaction between baseline LEA and sex on CVD mortality, with female sex conferring added risk of CVD mortality.

CONCLUSIONS

LEA is a potent predictor of all-cause and CVD mortality in diabetic American Indians. The combination of female sex and LEA is associated with greater risk of CVD mortality than either factor alone.

The impact of diabetes mellitus among the Métis of western Canada

OBJECTIVES

To examine the impact of diabetes mellitus on the lives of the Métis of western Canada, and to determine the extent of co-morbidity among Métis with diabetes.

DESIGN

The source of data was the Aboriginal Peoples Survey (APS), conducted by Statistics Canada in 1991. The survey was administered to a representative sample of Aboriginal peoples throughout Canada. Analysis was completed on self-identified Métis participants from the Canadian provinces of Manitoba, Saskatchewan and Alberta.

RESULTS

Métis participants with diabetes were more likely than those without diabetes to report their health status as poor. Significantly greater numbers of Métis with diabetes reported activity limitations at work, at home and in leisure activities, the need for assistance with activities of daily living and difficulties with ambulation than did those without diabetes. The extent of co-morbidity was also significant. Métis with diabetes were almost three times more likely to report hypertension and heart problems and twice as likely to report sight impairments than were those without diabetes.

CONCLUSIONS

This research represents the first account of the effects of diabetes on the lives of the Métis. The APS data have provided a clear picture of the impairments in physical functioning experienced by the Métis with diabetes and the impact upon quality of life. In addition, the strong associations between diabetes and hypertension, heart problems and sight impairments suggest profound morbidity in this population that warrants prompt attention.

Health-related quality of life of diabetic Pima Indians

This study was designed to measure the health-related quality of life of a sample of diabetic Pima Indians. Health status questionnaires were administered to 54 diabetic Pima Indians attending an outpatient pharmacy in southern Arizona. Health-related quality of life was assessed using the SF-36 Health Survey. Internal consistencies of the eight multi-item scales of the SF-36 were estimated. Nonparametric analyses were performed to determine relationships between mean SF-36 scale scores and various clinical and demographic variables. Favorable internal consistencies for the multi-item scales were observed, with alpha coefficients ranging from 0.63 to 0.91. SF-36 scale scores were not influenced by sex or education level. Age was significantly associated with four of the eight dimensions. Indicators of glycemic control were not significantly associated with any SF-36 multi-item scale scores. Subjects with more comorbid chronic conditions had significantly lower SF-36 scores. If the goal of maximizing health status of American Indians is to be reached, health-related quality-of-life assessment should be used as a means to monitor progress toward that goal. Further evaluation of the SF-36 or other health status/quality-of-life instruments in this population should be undertaken.