Improvements in risk factor control among persons with diabetes in the United States: Evidence and implications for remaining life expectancy

https://doi.org/10.1016/j.diabres.2009.09.017Get rights and content

Abstract

Aims

To examine whether A1c, blood pressure, and cholesterol values changed for U.S. adults with diagnosed diabetes between 1988–1994 and 2005–2006. We then project the impact of these changes on life expectancy and diabetes-related complications.

Methods

We estimated changes in hemoglobin A1c, blood pressure, and total cholesterol between 1988–1994 and 2005–2006 using regression analysis and data from the National Health and Nutrition Examination Survey. We projected the potential effects on life expectancy and complications using the CDC-RTI Diabetes Cost-Effectiveness Model.

Results

A1c fell by 0.68 percentage points (P = 0.001) among U.S. adults with diagnosed diabetes. Among those with diabetes and hypertension, systolic and diastolic blood pressure fell by 5.66 and 8.15 mmHg, respectively (P = 0.005 and P = 0.001). Among those with diabetes and high cholesterol, total cholesterol fell by 36.41 mg/dL (P = 0.001). These improvements were projected to increase life expectancy for persons with newly diagnosed diabetes by 1.0 year.

Conclusions

Risk factor control has improved in the United States. Persons newly diagnosed with type 2 diabetes in 2005 have a better prognosis than persons diagnosed with diabetes 11 years earlier.

Introduction

Good control of hemoglobin A1c (A1c), blood pressure, and lipid levels have all been well established as crucial to the reduction of risk for complications of diabetes [1], [2]. Accordingly, public health programs promote the ABCs (A1c, blood pressure, cholesterol) as a key component of clinical and public health interventions for diabetes in the United States [3]. Therefore, tracking national trends in A1c, blood pressure, and cholesterol is a priority.

Previous analyses have demonstrated reductions in blood pressure and cholesterol levels in persons with diabetes in the United States during the past 30 years [4]. Until recently, there was little evidence from nationally representative data that glycemic control had improved. Studies using National Health and Nutrition Examination Survey (NHANES) data found that A1c did not improve significantly between 1988–1994 and 1999–2002 [5], [6], [7]. Moreover, one study found no change in blood pressure levels between 1988–1994 and 1998–2002 [5].

Two studies using more recent NHANES data showed that A1c levels improved by about 0.5 percentage points between 1999–2000 and 2003–2004 [8], [9]. However, these studies did not examine whether blood pressure and cholesterol levels also changed during the period among persons with diabetes. Furthermore, no study has estimated the potential population-level impact of these changes on long-term health outcomes, including life expectancy and diabetes-related complications.

Here, we examine whether A1c, blood pressure, and cholesterol values changed for persons with diagnosed diabetes between NHANES III (1988–1994) and the latest NHANES wave (2005–2006). We then use a diabetes progression model to project the impact of risk factor changes on life expectancy and diabetes-related complications for U.S. adults newly diagnosed with diabetes.

Section snippets

Changes in risk factor control

We analyzed data from NHANES to assess temporal changes in selected risk factors. NHANES is a nationally representative, population-based survey designed to collect information on the health and nutrition of U.S. civilians. Participants respond to a household interview, and most complete clinical examinations. Additional details on the surveys are available elsewhere [10].

We estimated changes in hemoglobin A1c (measuring glycemic control), systolic (SBP) and diastolic (DBP) blood pressure

Results

Table 1 shows the (unweighted) number of observations used in the A1c, blood pressure, and cholesterol regressions by NHANES wave. Table 2 presents the explanatory variables for the baseline (NHANES III) and final (2005–2006) waves for the A1c regression. Fig. 1 shows unadjusted changes in A1c, blood pressure, and cholesterol across NHANES waves beginning with NHANES III. Table 3 shows 2005–2006 risk factor control relative to baseline after adjusting for other explanatory variables in the

Discussion

Our analysis indicates that risk factor control improved for persons with diabetes during the period between NHANES III (1988–1994) and NHANES 2005–2006. For A1c, most of the improvement occurred after 2000 or 2002. The source of the recent improvement in glycemic control is unclear. Possible sources include strengthened clinical guidelines, improved diabetes disease management programs, improved delivery of diabetes care services in the health system, enhanced public health education, and the

Conflict of interest

We declare that we have no conflict of interest.

Acknowledgments

This research was supported by funding (Contract # 200-2002-00776) from CDC, which supported the study's design and implementation. The findings and conclusions in this article are solely those of the authors and do not necessarily reflect the official position of CDC. Steven Couper provided research assistance.

References (29)

  • E.S. Ford et al.

    Trends in A1c concentrations among US adults with diagnosed diabetes from 1999 to 2004

    Diabetes Care

    (2008)
  • National Center for Health Statistics, National Health and Nutrition Examination Summary, Data Sets and Related...
  • StataCorp.

    Stata Statistical Software, Release 9

    (2005)
  • National Center for Health Statistics, HDL Cholesterol, U.S. Department of Health and Human Service, Centers for...
  • Cited by (27)

    • Temporal trends of patients with acute coronary syndrome and multi-vessel coronary artery disease - from the ACSIS registry

      2020, International Journal of Cardiology
      Citation Excerpt :

      Evidence supporting MV-PCI in NSTE-ACS exist as well yet these are less substantiated [49]. In consistence with previously reported trends [23–28,50] we found that discharge with guideline recommended antithrombotic and lipid lowering pharmacotherapy has increased throughout the investigation period while the proportion of patients discharged on beta-blockers (BB) and angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB) remained constant. With partial agreement with our findings, Makam et al. [50] found an increase in all groups of medications in 11 Massachusetts hospitals, United States, between the years 2001–2011.

    • Ethnical disparities in temporal trends of acute myocardial infarction (AMI) throughout a decade in Israel. Soroka acute myocardial infarction (SAMI-II) project

      2016, International Journal of Cardiology
      Citation Excerpt :

      The persistent decrease in an AMI hospitalization rate is in coherence with reports from other parts of the world [8,11,26] and probably reflects the primary and secondary prevention efforts worldwide and in our country. Increased adherence with treatment guidelines [27], improved and earlier management of risk factors overtime [28–31], increased use of cardioprotective medications (e.g. aspirin, beta-blockers, angiotensin-converting-enzyme inhibitor and statins) [26,32,33] and revascularization [27,33–35] have been reported. In the current study we found that the decline in the adjusted AMI incidence was more prominent and steeper among Bedouins throughout the study period.

    • Temporal trends in acute myocardial infarction: What about survival of hospital survivors? Disparities between STEMI & NSTEMI remain. Soroka acute myocardial infarction II (SAMI-II) project

      2016, International Journal of Cardiology
      Citation Excerpt :

      These findings are consistent with the findings of previous reports [9,11]. The latter decline could possibly result from increased adherence with treatment guidelines [13,14], improved and earlier management of risk factors overtime [15–18], increased use of cardioprotective medications (e.g. aspirin, beta-blockers and statins) [11,19,20] and increased use of interventions (e.g. PCI and CABG) and particularly the new-generation of DES [21] that reduce the occurrence or the severity of subsequent re-infarctions [13,20,22,23]. The early increase in the incidence of NSTEMI with stabilization thereafter could be attributable, at least partially, to the increased sensitivity and more frequent use of troponin analyses consistent with previous reports [11,24–26].

    • Primary and Secondary Prevention Strategy for Cardiovascular Disease in Diabetes Mellitus

      2011, Cardiology Clinics
      Citation Excerpt :

      So the question arises as to how well this is being incorporated in clinical practice. A recent study reported on the improving trends seen in the management of diabetes mellitus and attendant CV disease based on NHANES data.77 Changes in HbA1c, blood pressure, and total cholesterol were estimated between 1988 and 1994 and between 2005 and 2006 using regression analysis and data from the NHANES.

    View all citing articles on Scopus
    View full text