Assessment of differentially methylated loci in individuals with end-stage kidney disease attributed to diabetic kidney disease: an exploratory study.

BACKGROUND: A subset of individuals with type 1 diabetes mellitus (T1DM) are predisposed to developing diabetic kidney disease (DKD), the most common cause globally of end-stage kidney disease (ESKD). Emerging evidence suggests epigenetic changes in DNA methylation may have a causal role in both T1DM and DKD. The aim of this exploratory investigation was to assess differences in blood-derived DNA methylation patterns between individuals with T1DM-ESKD and individuals with long-duration T1DM but no evidence of kidney disease upon repeated testing to identify potential blood-based biomarkers. Blood-derived DNA from individuals (107 cases, 253 controls and 14 experimental controls) were bisulphite treated before DNA methylation patterns from both groups were generated and analysed using Illumina's Infinium MethylationEPIC BeadChip arrays (n = 862,927 sites). Differentially methylated CpG sites (dmCpGs) were identified (false discovery rate adjusted p ≤ × 10-8 and fold change ± 2) by comparing methylation levels between ESKD cases and T1DM controls at single site resolution. Gene annotation and functionality was investigated to enrich and rank methylated regions associated with ESKD in T1DM. RESULTS: Top-ranked genes within which several dmCpGs were located and supported by functional data with methylation look-ups in other cohorts include: AFF3, ARID5B, CUX1, ELMO1, FKBP5, HDAC4, ITGAL, LY9, PIM1, RUNX3, SEPTIN9 and UPF3A. Top-ranked enrichment pathways included pathways in cancer, TGF-ß signalling and Th17 cell differentiation. CONCLUSIONS: Epigenetic alterations provide a dynamic link between an individual's genetic background and their environmental exposures. This robust evaluation of DNA methylation in carefully phenotyped individuals has identified biomarkers associated with ESKD, revealing several genes and implicated key pathways associated with ESKD in individuals with T1DM.

Secular changes in physical growth and obesity among southwestern American Indian children over four decades.

BACKGROUND AND OBJECTIVES: Most studies describing childhood obesity in the United States are based on cross-sectional surveys and do not include substantial numbers of American Indians (AI). Secular trends in height and weight reflect general health status. This study describes weight trends and transitions among AI children over a 43-year period. METHODS: Anthropometric data were obtained from a prospective study conducted in a southwestern US AI population (1965 through 2007). For cross-sectional analysis, 12 377 observations were available from 6529 children across four birth cohorts (1955-1964, 1965-1974, 1975-1984, 1985-1994). Participants were stratified into three age groups: pre- (5-9 years), early (10-13) and late (14-17) adolescence. Longitudinal analyses included 1737 children with one exam in each age group. RESULTS: In early and late adolescence, weight increased across birth cohorts. Prevalence of obesity among pre-adolescents was 17.5% (95% CI, 15.1%-19.9%) in the 1955-1964 cohort and 33.7% (95% CI, 30.1%-36.4%) in the 1985-1994 cohort. 74% of children overweight in pre-adolescence in the 1985-1994 cohort became obese by late adolescence; in the 1955-1964 cohort, only 43% made this transition. CONCLUSIONS: This study describes the rising prevalence of childhood obesity. Children obese in pre-adolescence remained obese in late adolescence, stressing the need for early intervention.

Harmonic Vibrational Frequencies: Approximate Global Scaling Factors for TPSS, M06, and M11 Functional Families Using Several Common Basis Sets.

We propose new approximate global multiplicative scaling factors for the DFT calculation of ground state harmonic vibrational frequencies using functionals from the TPSS, M06, and M11 functional families with standard correlation consistent cc-pVxZ and aug-cc-pVxZ (x = D, T, and Q), 6-311G split valence family, Sadlej and Sapporo polarized triple-ζ basis sets. Results for B3LYP, CAM-B3LYP, B3PW91, PBE, and PBE0 functionals with these basis sets are also reported. A total of 99 harmonic frequencies were calculated for 26 gas-phase organic and nonorganic molecules typically found in detonated solid propellant residue. Our proposed approximate multiplicative scaling factors are determined using a least-squares approach comparing the computed harmonic frequencies to experimental counterparts well established in the scientific literature. A comparison of our work to previously published global scaling factors is made to verify method reliability and the applicability of our molecular test set.

Cardiometabolic risk profile based on body mass index in American Indian children and adolescents.

BACKGROUND: Childhood obesity is associated with increased cardiometabolic risk. OBJECTIVE: To study the relationship between body mass index (BMI) and cardiometabolic risk factors in American Indian children and adolescents. METHODS: Differences in metabolic variables by age and sex-specific BMI percentiles (2000 Centers for Disease Control and Prevention Growth Charts) were examined in a cross-sectional analysis of 2977 individuals across three age categories. Children with an exam in two consecutive age categories were included in a longitudinal analysis. Spearman's correlations were used to test the association of BMI percentile with anthropometric and biochemical variables. RESULTS: Body mass index percentile correlated with systolic (r = 0.24 to 0.38) and diastolic (r = 0.13 to 0.22) blood pressure, fasting plasma glucose (r = 0.20 to 0.33), 2-h plasma glucose (r = 0.30 to 0.46), total cholesterol (r = 0.12 to 0.23), serum triglycerides (r = 0.40 to 0.51) and HDL cholesterol (r = -0.36 to -0.43) in each age group (5-9, 10-13 and 14-17 years). Among participants examined in multiple age categories, BMI percentile increased over time. Change in BMI percentile from one age category to the next was associated with an increase in fasting glucose, 2-h glucose and triglycerides and a decrease in HDL cholesterol. CONCLUSION: Higher BMI was associated with blood pressure elevation, hyperglycaemia and dyslipidaemia in American Indian children and adolescents.

Predicting decline of kidney function in lupus nephritis using urine biomarkers.

OBJECTIVE: To evaluate candidate biomarkers to predict future renal function decline (RFD) in children and adults with lupus nephritis (LN). METHODS: At the time of enrollment into prospective observational LN cohort studies liver-type fatty acid binding protein (LFABP), albumin, monocyte chemoattractant protein-1 (MCP-1), uromodulin, transferrin, and hepcidin were measured in urine samples of two cohorts of patients with LN, one followed at a pediatric (cohort-1; n = 28) and one at an adult institution (cohort-2; n = 69). The primary outcome was RFD, defined in cohort-1 as a decrease in estimated glomerular filtration rate (eGFR) of ≥20% and in cohort-2 as a sustained increase of ≥25% in serum creatinine concentration (SCr), both from baseline. RESULTS: All patients (n = 97) had normal eGFR or SCr at the time of urine collection at baseline. RFD occurred in 29% (8/28) of patients in cohort-1 during a mean follow-up of 6.1 months, and in 30% (21/69) of those in cohort-2 during a mean follow-up of 60 months. Individually, in cohort-1, levels of MCP-1, transferrin, LFABP, and albumin were higher in the RFD group than those who maintained renal function, with statistical significance for LFABP and albumin. In cohort-2 the RFD group also had higher levels of urine MCP-1 and albumin than others. The combination of LFABP, MCP-1, albumin, and transferrin had good predictive accuracy for RFD in both cohorts (area under the ROC curve = 0.77-0.82). CONCLUSION: The combinatorial urine biomarker LFABP, MCP-1, albumin, and transferrin shows promise as a predictor of renal functional decline in LN, and warrants further investigation.

HLA-DRB1 reduces the risk of type 2 diabetes mellitus by increased insulin secretion.

AIMS/HYPOTHESIS: We sought to identify the physiological implications of genetic variation at the HLA-DRB1 region in full-heritage Pima Indians in Arizona. METHODS: Single-nucleotide polymorphisms from the HLA region on chromosome 6p were tested for association with skeletal muscle mRNA expression of HLA-DRB1 and HLA-DRA, and with type 2 diabetes mellitus and prediabetic traits. RESULTS: The A allele at rs9268852, which tags HLA-DRB1 02(1602), was associated both with higher HLA-DRB1 mRNA expression (n = 133, p = 4.27 × 10(-14)) and decreased risk of type 2 diabetes (n = 3,265, OR 0.723, p = 0.002). Among persons with normal glucose tolerance (n = 266) this allele was associated with a higher mean acute insulin response during an intravenous glucose tolerance test (p = 0.005), higher mean 30 min insulin concentration during an oral glucose tolerance test (p = 0.017) and higher body fat percentage (p = 0.010). The polymorphism was not associated with HLA-DRA mRNA expression or insulin sensitivity. CONCLUSIONS/INTERPRETATION: HLA-DRB1*02 is protective for type 2 diabetes, probably by enhancing self tolerance, thereby protecting against the autoimmune-mediated reduction of insulin secretion.

The impact of disadvantage on the development and progression of diabetic kidney disease.

BACKGROUND: Disadvantaged people include those experiencing economic, social or educational deprivation and, in some cases, those undergoing rapid transition from subsistence to industrial economies. Disadvantaged people worldwide are affected disproportionately by the global epidemic of diabetes. They are also at increased risk of kidney disease attributable to diabetes, and for many, the cost of managing their kidney disease far exceeds their available resources. METHODS: We review factors associated with disadvantage that may increase the risk of diabetic kidney disease, and the barriers to care that hinder attempts to provide an adequate therapeutic response. RESULTS AND CONCLUSIONS: A rapidly rising prevalence and magnitude of obesity among children and adults, increasing frequency of intrauterine exposure to diabetes, and inadequate access to healthcare are responsible, in part, for a surge in the frequency of diabetes and, in turn, diabetic kidney disease among disadvantaged people. These factors may also predispose to an earlier onset of diabetes and kidney disease, thereby perpetuating the disadvantage by reducing the earning potential of those affected through illness and disability.

Correlations of random binary sequences with pre-stated operator intention: a review of a 12-year program.

Strong correlations between output distribution means of a variety of random binary processes and pre-stated intentions of some 100 individual human operators have been established over a 12-year experimental program. More than 1000 experimental series, employing four different categories of random devices and several distinctive protocols, show comparable magnitudes of anomalous mean shifts from chance expectation, with similar distribution structures. Although the absolute effect sizes are quite small, of the order of 10(-4) bits deviation per bit processed, over the huge databases accumulated, the composite effect exceeds 7sigma (p approximately 3.5 x 10(-13)). These data display significant disparities between female and male operator performances, and consistent serial position effects in individual and collective results. Data generated by operators far removed from the machines and exerting their efforts at times other than those of machine operation show similar effect sizes and structural details to those of the local, on-time experiments. Most other secondary parameters tested are found to have little effect on the scale and character of the results, with one important exception: studies performed using fully deterministic pseudorandom sources, either hard-wired or algorithmic, yield null overall mean shifts, and display no other anomalous features.

Increasing incidence of proteinuria and declining incidence of end-stage renal disease in diabetic Pima Indians.

The introduction of more efficacious treatments for diabetic kidney disease may slow its progression, but evidence for their effectiveness in populations is sparse. We examined trends in the incidence of clinical proteinuria, defined as a urinary protein-to-creatinine ratio >0.5 g/g, and diabetic end-stage renal disease (ESRD), defined as death from diabetic nephropathy or onset of dialysis, in Pima Indians with type 2 diabetes between 1967 and 2002. The study included 2189 diabetic subjects >/=25 years old. During follow-up, 366 incident cases of proteinuria occurred in the subset of 1715 subjects without proteinuria at baseline. The age-sex-adjusted incidence rate of proteinuria increased from 24.3 cases/1000 person-years (pyrs) (95% confidence interval (CI) 18.7-30.0) in 1967-1978 to 35.4 cases/1000 pyrs (95% CI 28.1-42.8) in 1979-1990 and 38.9 cases/1000 pyrs (95% CI 31.2-46.5) in 1991-2002 (P(trend)<0.0002). In each period, the age-sex-adjusted incidence of proteinuria increased with diabetes duration, but diabetes duration-specific incidence was stable throughout the study period (P=0.8). The age-sex-adjusted incidence of ESRD increased between 1967 and 1990 and declined thereafter. The incidence of proteinuria increased over 36 years in Pima Indians as the proportion of people with diabetes of long duration increased. On the other hand, the incidence of ESRD declined after 1990, coinciding with improved control of blood pressure, hyperglycemia, and perhaps other risk factors.

Variants in the gene encoding aldose reductase (AKR1B1) and diabetic nephropathy in American Indians.

AIMS: The aldose reductase gene (AKR1B1) is a strong candidate for diabetic nephropathy, and the T allele at rs759853 and the Z-2 allele at an [AC]n microsatellite are associated with diabetic kidney disease in some populations. As AKR1B1 is located on 7q35, where we have previously reported linkage to diabetic nephropathy in Pima Indians, this study examined the association of AKR1B1 variants with diabetic nephropathy in this population. METHODS: AKR1B1 variants were identified by sequencing and genotyped using allelic discrimination and pyrosequencing. Genotype distributions were compared between 107 cases with diabetic end-stage renal disease and 108 control subjects with diabetes for > or = 10 years and no evidence of nephropathy, and between 141 individuals with nephropathy and 416 individuals without heavy proteinuria in a family study of 257 sibships. RESULTS: We identified 11 AKR1B1 single nucleotide polymorphisms (SNPs) and the [AC]n microsatellite polymorphism. Three SNPs were rare and two were in 100% genotypic concordance; thus, eight polymorphisms were genotyped. No variant was associated with diabetic kidney disease in the case-control or family-based study. For example, the T allele at rs759853 had an allele frequency of 0.165 in cases and 0.171 in control subjects (OR = 0.96, 95% CI, 0.57-1.59, P = 0.86); in the family study its frequency was 0.140 and 0.169 in affected and unaffected individuals, respectively (OR = 0.90, 95% CI, 0.53-1.54 P = 0.71). Corresponding values for the Z-2 allele at the [AC]n microsatellite were OR = 1.09 (95% CI 0.72-1.66, P = 0.67) and OR = 1.25 (95% CI 0.81-1.95, P = 0.31) in the case-control and family studies, respectively. CONCLUSIONS: Common AKR1B1 polymorphisms are unlikely to be major determinants of diabetic nephropathy in this population.

Alpha-oxoaldehyde metabolism and diabetic complications.

The factors responsible for variable susceptibility to diabetic nephropathy are not clear. According to the non-enzymatic glycation hypothesis, diabetes-related tissue damage occurs due to a complex mixture of toxic products, including alpha-oxoaldehydes, which are inherently toxic as well as serving as precursors for advanced glycation end-products. Protective mechanisms exist to control this unavoidable glycation, and these are determined by genetic or environmental factors that can regulate the concentrations of the reactive sugars or end-products. In diabetes these protective mechanisms become more important, since glycation stress increases, and less efficient defence systems against this stress could lead to diabetic complications. Some of these enzymatic control mechanisms, including those that regulate alpha-oxoaldehydes, have been identified. We have observed significant increases in production of the alpha-oxoaldehydes methylglyoxal and 3-deoxyglucosone in three human populations with biopsy-proven progression of nephropathy. The increase in methylglyoxal could be secondary to defects in downstream glycolytic enzymes (such as glyceraldehyde-3-phosphate dehydrogenase) that regulate its production, or in detoxification mechanisms such as glyoxalase. Other mechanisms, however, appear to be responsible for the observed increase in 3-deoxyglucosone levels. We present results of our studies on the mechanisms responsible for variable production of alpha-oxoaldehydes by measuring the activity and characteristics of these enzymes in cells from complication-prone and -resistant diabetic patients. New therapeutic interventions designed to control these endogenous mechanisms could potentially enhance protection against excessive glycation and prevent or reverse complications of long-term diabetes.

Dicyclic and tricyclic diaminopyrimidine derivatives as potent inhibitors of Cryptosporidium parvum dihydrofolate reductase: structure-activity and structure-selectivity correlations.

A structurally diverse library of 93 lipophilic di- and tricyclic diaminopyrimidine derivatives was tested for the ability to inhibit recombinant dihydrofolate reductase (DHFR) cloned from human and bovine isolates of Cryptosporidium parvum (J. R. Vásquez et al., Mol. Biochem. Parasitol. 79:153-165, 1996). In parallel, the library was also tested against human DHFR and, for comparison, the enzyme from Escherichia coli. Fifty percent inhibitory concentrations (IC(50)s) were determined by means of a standard spectrophotometric assay of DHFR activity with dihydrofolate and NADPH as the cosubstrates. Of the compounds tested, 25 had IC(50)s in the 1 to 10 microM range against one or both C. parvum enzymes and thus were not substantially different from trimethoprim (IC(50)s, ca. 4 microM). Another 25 compounds had IC(50)s of <1.0 microM, and 9 of these had IC(50)s of <0.1 microM and thus were at least 40 times more potent than trimethoprim. The remaining 42 compounds were weak inhibitors (IC(50)s, >10 microM) and thus were not considered to be of interest as drugs useful against this organism. A good correlation was generally obtained between the results of the spectrophotometric enzyme inhibition assays and those obtained recently in a yeast complementation assay (V. H. Brophy et al., Antimicrob. Agents Chemother. 44:1019-1028, 2000; H. Lau et al., Antimicrob. Agents Chemother. 45:187-195, 2001). Although many of the compounds in the library were more potent than trimethoprim, none had the degree of selectivity of trimethoprim for C. parvum versus human DHFR. Collectively, the results of these assays comprise the largest available database of lipophilic antifolates as potential anticryptosporidial agents. The compounds in the library were also tested as inhibitors of the proliferation of intracellular C. parvum oocysts in canine kidney epithelial cells cultured in folate-free medium containing thymidine (10 microM) and hypoxanthine (100 microM). After 72 h of drug exposure, the number of parasites inside the cells was quantitated by indirect immunofluorescence microscopy. Sixteen compounds had IC(50)s of <3 microM, and five of these had IC(50)s of <0.3 microM and thus were comparable in potency to trimetrexate. The finding that submicromolar concentrations of several of the compounds in the library could inhibit in vitro growth of C. parvum in host cells in the presence of thymidine (dThd) and hypoxanthine (Hx) suggests that lipophilic DHFR inhibitors, in combination with leucovorin, may find use in the treatment of intractable C. parvum infections.

Characterization of a monoclonal antibody reacting with antigen-4 domain of gp900 in Cryptosporidium parvum invasive stages.

Cryptosporidium parvum (Protozoa, Apicomplexa) infects the apical surface of intestinal epithelial cells, where it grows and divides within a membrane-bound parasitophorous vacuole. gp900, an abundant glycoprotein of C. parvum merozoites and sporozoites, is localized in micronemes and at the surface of invasive stages and participates in the invasion process. Here, we describe a new monoclonal antibody (mAb) against gp900. As shown by immunofluorescence of excysted parasites and immunoelectron microscopy of infected tissues, the mAb reacted with micronemes present in the apical pole of invasive stages. In immunoprecipitation experiments, the mAb was shown to react with a high molecular weight antigen co-migrating with gp900. Finally, three reactive clones were selected upon screening of a C. parvum genomic expression library with the mAb; and sequencing of the insert from one of them showed a 596 bp sequence identical to the DNA region encoding a domain of gp900 identified as antigen 4.

The effect of Indian or Anglo dietary preference on the incidence of diabetes in Pima Indians.

OBJECTIVE: In short-term studies, adoption of a traditional diet is associated with reduction in metabolic abnormalities often found in populations experiencing rapid lifestyle changes. We examined the long-term effects of a self-assessed traditional or nontraditional dietary pattern on the development of type 2 diabetes in 165 nondiabetic Pima Indians. RESEARCH DESIGN AND METHODS: Dietary intake was assessed in 1988 by a quantitative food frequency method, and subjects were asked to classify their diet as "Indian," "Anglo," or "mixed." The Indian diet reflects a preference for Sonoran-style and traditional desert foods. The Anglo diet reflects a preference for non-Sonoran-style foods typical of the remaining regions of the U.S. RESULTS: In women, the intake of complex carbohydrates, dietary fiber, insoluble fiber, vegetable proteins, and the proportion of total calories from complex carbohydrate and vegetable proteins were significantly higher (P < 0.05) in the Indian than in the Anglo diet. The mixed diet was intermediate in of all these constituents. In men, the intake for these nutrients was also higher in the Indian than in the Anglo group, but not significantly. Diabetes developed in 36 subjects (8 men and 28 women) during 6.2 years of follow-up (range 0.9-10.9). The crude incidence rates of diabetes were 23. 35, and 63 cases per 1,000 person-years in the Indian. mixed, and Anglo groups, respectively. After adjustment for age, sex, BMI, and total energy intake in a proportional hazards model, the risk of developing diabetes in the Anglo-diet group was 2.5 times as high (95%) CI 0.9-7.2) and the rate in the mixed-diet group was 1.3 times as high (0.6-3.3) as in the Indian-diet group. CONCLUSIONS: This study suggests that the adoption of an Anglo diet may increase the risk of developing diabetes in Pima Indians, but it does not provide unequivocal evidence for or against this hypothesis.

Genetics of diabetic nephropathy in the Pima Indians.

Diabetic nephropathy is the leading cause of renal failure in industrialized countries. There is strong evidence that diabetic nephropathy is influenced by genetic factors. Studies in the Pima Indians as well as in other populations demonstrate that diabetic nephropathy aggregates in families. The hypothesis that the familial aggregation reflects the effect of a major gene was formally tested by segregation analysis of diabetic nephropathy in Pima Indians with type 2 diabetes. The segregation analysis provided strong evidence for a major genetic effect on the prevalence of diabetic nephropathy; this suggests that some of the genetic determinants of diabetic nephropathy may have effects of sufficient magnitude to be detected by linkage analysis. Therefore, we analyzed data from a genome-wide scan to identify susceptibility loci for nephropathy in diabetic Pima Indians. Analyses conducted by both parametric (model-based) and nonparametric methods revealed tentative evidence for nephropathy susceptibility loci on chromosomes 3q, 7q, 18q, and 20p.

Evolution of incipient nephropathy in type 2 diabetes mellitus.

BACKGROUND: We examined the course of glomerular injury in 12 Pima Indians with long-standing (>8 years) type 2 diabetes mellitus, normal serum creatinine, and microalbuminuria. They were compared with a group of 10 Pima Indians in Arizona with new-onset (<5 years) type 2 diabetes, normal renal function, and normoalbuminuria (<30 mg albumin/g creatinine on random urine specimens). METHODS: A combination of physiological and morphological techniques was used to evaluate glomerular function and structure serially on two occasions separated by a 48-month interval. Clearances of iothalamate and p-aminohippuric acid were used to determine glomerular filtration rate (GFR) and renal plasma flow, respectively. Afferent oncotic pressure was determined by membrane osmometry. The single nephron ultrafiltration coefficient (Kf) was determined by morphometric analysis of glomeruli and mathematical modeling. RESULTS: The urinary albumin-to-creatinine ratio (median + range) increased from 84 (28 to 415) to 260 (31 to 2232) mg/g between the two examinations (P = 0.01), and 6 of 12 patients advanced from incipient (ratio = 30 to 299 mg/g) to overt nephropathy (>/=300 mg/g). A 17% decline in GFR between the two examinations from 186 +/- 41 to 155 +/- 50 mL/min (mean +/- SD; P = 0.06) was accompanied by a 17% decline in renal plasma flow (P = 0.003) and a 6% increase in plasma oncotic pressure (P = 0.02). Computed glomerular hydraulic permeability was depressed by 13% below control values at both examinations, a result of a widened basement membrane and a reduction in frequency of epithelial filtration slits. The filtration surface area declined significantly, however, from 6.96 +/- 2.53 to 5.51 +/- 1.62 x 105 mm2 (P = 0.01), a change that was accompanied by a significant decline in the number of mesangial cells (P = 0.001), endothelial cells (P = 0.038), and podocytes (P = 0.0005). These changes lowered single nephron Kf by 20% from 16.5 +/- 6.0 to 13.2 +/- 3.6 nL/(minutes + mm Hg) between the two examinations (P = 0.02). Multiple linear regression analysis revealed that among the determinants of GFR, only the change in single nephron Kf was related to the corresponding change in GFR. CONCLUSION: We conclude that a reduction in Kf is the major determinant of a decline in GFR from an elevated toward a normal range as nephropathy in type 2 diabetes advances from an incipient to an overt stage.

Diabetes duration and cause-specific mortality in the Verona Diabetes Study.

OBJECTIVE: To examine the 10-year mortality and effect of diabetes duration on overall and cause-specific mortality in diabetic subjects in the Verona Diabetes Study (VDS). RESEARCH DESIGN AND METHODS: Records from diabetes clinics, family physicians, and a drug consumption database were used to identify 5,818 subjects > or =45 years of age with type 2 diabetes who were alive and residing in Verona, Italy on 31 December 1986. Vital status of each subject was ascertained on 31 December 1996. Underlying causes of death were determined from death certificates. Death rates and death rate ratios (DRRs) were computed and standardized to the population of Verona in 1991. RESULTS: During the study, 2,328 subjects died; 974 deaths were attributable to cardiovascular disease, 517 to neoplasms, 324 to diabetes-related diseases, 134 to digestive diseases, 250 to other natural causes, and 48 to external causes. There were 81 subjects who died of unknown causes. Death rates from natural causes were higher in men than in women (DRR 1.4, 95% CI 1.2-1.5) and rose in both sexes with increasing duration of diabetes (P = 0.001). Among the natural causes of death, those for diabetes-related diseases were strongly related to diabetes duration (P = 0.001). a modest relationship with duration was also found for ischemic heart disease in men (P = 0.07). CONCLUSIONS: Cardiovascular disease was the principal cause of death among people with type 2 diabetes in the VDS. Rates for natural causes of death rose with increasing duration of diabetes. Deaths from diabetes-related diseases in both sexes and from ischemic heart disease in men were largely responsible for this increase.

Do foot examinations reduce the risk of diabetic amputation?

BACKGROUND: Foot examinations are widely recommended as a means to reduce amputation risk, but no investigators have studied their independent effect on this outcome. METHODS: We conducted a population-based case-control study of primary care provided to Pima Indians from the Gila River Indian Community. Sixty-one Pima Indians with type 2 diabetes and a first lower-extremity amputation between January 1, 1985, and December 31, 1992, were compared with 183 people who had no amputation by December 31, 1992. The type of foot examination conducted, comorbid conditions, and foot risk factors present in the 36 months before the pivotal event were abstracted from medical records. All ulcer care was excluded. The independent effect of foot examinations on the risk of amputation was assessed by logistic regression. RESULTS: During the 36 study months, 1857 foot examinations were performed on 244 subjects. The median number of preventive foot examinations was 7 for case patients and 3 for control patients. After controlling for differences in comorbid conditions and foot risk conditions, the risk of amputation for persons with 1 or more foot examinations was an odds ratio (OR) of 0.55 (95% confidence interval [CI], 0.2-1.7; P=.31). The risk of amputation associated with written comments of nonadherence with therapeutic foot care recommendations or diabetic medication was an OR of 1.9 (95% CI, 0.9-4.3; P=.10). CONCLUSIONS: Our study failed to demonstrate that foot examinations decrease the risk of amputation in Pima Indians with type 2 diabetes. However, foot examinations detect high-risk conditions for which specific interventions have been shown to be effective in reducing amputation risk.