Journal of Diabetes and Its Complications 28 (2014) 257–258
Contents lists available at ScienceDirect
Journal of Diabetes and Its Complications journal homepage: WWW.JDCJOURNAL.COM
Physical activity in diabetes: Is any better than none?
In the United States, 13% of adults have diabetes and an additional 30% are at high risk of developing diabetes (Cowie et al., 2009). Because diabetes increases the risk of vascular morbidity and mortality (The Emerging Risk Factors Collaboration, 2010), lifestyle modification and pharmacologic therapy are recommended (American Diabetes Association, 2013; Inzucchi et al., 2012) for clinical management and to prevent complications. In this issue of the Journal, Brown and colleagues (2014) investigated the association of lifestyle modification and pharmacologic therapy for type 2 diabetes mellitus (T2DM) with allcause and cardiovascular disease (CVD) mortality. Using data for adults ages ≥40 years, the authors investigated whether physical activity (PA) (defined as ≥1 PA weekly versus no PA weekly), pharmacologic therapy use (defined as treated with insulin or oral hypoglycemic medications versus not treated with insulin or oral hypoglycemic medications), and glycemic control (defined as HbA1c b 7.0% versus HbA1c ≥ 7%) were associated with risk of mortality. The authors classified participants with T2DM as 1) treated and controlled; 2) untreated and controlled; 3) treated and uncontrolled; 4) untreated and uncontrolled and further stratified their analyses by PA within each classification. The primary finding was that compared with individuals with T2DM who were physically active, treated, and controlled, individuals with T2DM who were physically inactive within each classification had an increased risk of all-cause and CVD mortality. Additionally, the mortality risk for individuals with T2DM who were physically active, treated, and controlled was similar to the mortality risk for those who did not have T2DM who were or were not physically active. The findings by Brown et al. suggest that PA as little as once weekly, which is less than the current PA recommendation, may yield health benefits for individuals with T2DM regardless of glycemic control or pharmacologic therapy use. The inverse association of PA with mortality risk among individuals with T2DM has been reported previously. Two meta-analyses reported PA decreased the risk of mortality among individuals with T2DM, with those in the highest PA category having a 40% lower risk of all-cause (Kodama et al., 2013; Sluik et al., 2012) and CVD mortality (Sluik et al., 2012) than those in the lowest PA category. Furthermore, a metaanalysis of the effect of PA on glycemic control among individuals with T2DM found that PA interventions, compared with no PA, resulted in lower HbA1c despite no significant weight change (Boulé, Haddad, Kenny, Wells, & Sigal, 2001). Individuals with T2DM are often overweight or obese, therefore many intervention studies have focused on weight reduction, with PA often included as part of the intervention, and have been mostly short-term (Norris et al., 2005). However, one multi-center randomized controlled trial, the Action for Health in Diabetes Study (Look AHEAD), evaluated the long-term effect of an Disclosures: Dr. Carson has received research support from Amgen, Inc.; Dr. Williams has no disclosures; and Dr. Hill is a scientific advisory board member for Sanofi-Aventis. 1056-8727/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jdiacomp.2013.10.012
intensive lifestyle intervention, which included 175 min of moderate intensity PA weekly as one of the components, among overweight and obese individuals with T2DM. After a median follow-up of 9.6 years, the intensive lifestyle intervention did not reduce CVD morbidity, all-cause mortality, or CVD mortality rates compared with the control group that received diabetes support and education (The Look AHEAD Research Group, 2013). Although the intervention did not result in any overall benefits for CVD morbidity or mortality, the intervention group did experience greater increases in PA (Jakicic et al., 2013), improvements in HbA1c and cardiovascular risk factors (The Look AHEAD Research Group, 2013), and the remission of diabetes (Gregg et al., 2012). Lifestyle interventions that include PA as one of the components have been shown to be effective for preventing T2DM. In the Diabetes Prevention Program, individuals at high risk for T2DM who received an intensive lifestyle intervention experienced 58% and 39% reductions in incident diabetes compared with the placebo and metformin groups, respectively (Knowler et al., 2002). Although 74% individuals in the intervention group met the PA goal at 6 months and 67% met the PA goal long-term (Wing et al., 2004), weight loss was the primary contributor to the reduced risk of diabetes overall. However, among individuals who did not meet the weight loss goal, those who met the PA goal had a lower risk of diabetes than those who did not meet the PA goal (Hamman et al., 2006). In the study by Brown et al., PA was associated with a lower risk of mortality among individuals with T2DM, even when glycemic control had been achieved. The appropriate HbA1c level for individuals with diabetes remains controversial, given randomized controlled trials that have reported no effect, and possible harm, associated with intensive glycemic control to HbA1c targets of b 6% or b6.5%, respectively, and mortality (Skyler et al., 2009). Current guidelines recommend a glycemic goal of HbA1c b 7% for many, but not all, adults with T2DM (American Diabetes Association, 2013). Brown and colleagues used this cut-point in their analyses, but this approach may obscure possible differential effects of PA across the spectrum of glycemic control (Calles-Escandon et al., 2010; Desouza, Bolli, & Fonseca, 2010), particularly for individuals with glycemic levels that are furthest from the recommended goal who have an increased risk of mortality (Nicholas, Charlton, Dregan, & Gulliford, 2013). The observational findings by Brown et al. suggest that PA, even as little as ≥ 1 time per week, may provide a mortality benefit for individuals with T2DM, but their study has several potential limitations. The authors did not use sampling weights to account for the survey sampling methods, so their findings are not representative of the US population and may be over- or underestimates of the PA and mortality association. Also, PA ≥ 1 time per week is a wide classification without an upper boundary, so it is possible that the association of PA with mortality among individuals with T2DM varies
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Editorial / Journal of Diabetes and Its Complications 28 (2014) 257–258
according to the duration and frequency of PA. The current clinical recommendation for adults with T2DM is moderate to vigorous PA for 150 min weekly (Colberg et al., 2010), yet the majority do not attain this level of activity (Morrato, Hill, Wyatt, Ghushchyan, & Sullivan, 2007). The primary goal of treatment in diabetes focuses on achieving and maintaining optimal glycemic levels, but lifestyle modification, including PA, will remain central to the long-term clinical management of diabetes. It may be advantageous for individuals with T2DM to make incremental gains toward the recommended PA level because of its demonstrated glycemic benefits; however, further investigation of the glycemic and vascular effects of PA among individuals with T2DM is warranted.
References American Diabetes Association. (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36, S11–S66. Boulé, N. G., Haddad, E., Kenny, G. P., Wells, G. A., & Sigal, R. J. (2001). Effects of exercise on glycemic control and body mass in type 2 diabetes mellitus: A meta-analysis of controlled clinical trials. JAMA: The Journal of the American Medical Association, 286, 1218–1227. Brown, R. E., Riddell, M. C., Macpherson, A. K., Canning, K. L., & Kuk, J. L. (2014). All-cause and cardiovascular mortality risk in U.S. adults with and without type 2 diabetes: Influence of physical activity, pharmacological treament and glycemic control. Journal of Diabetes and Its Complications, 28(3), 311–315. Calles-Escandon, J., Lovato, L. C., Simons-Morton, D. G., Kendall, D. M., Pop-Busui, R., Cohen, R. M., et al. (2010). Effect of intensive compared with standard glycemia treatment strategies on mortality by baseline subgroup characteristics: The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Diabetes Care, 33, 721–727. Colberg, S. R., Sigal, R. J., Fernhall, B., Regensteiner, J. G., Blissmer, B. J., Rubin, R. R., et al. (2010). Exercise and type 2 diabetes: The American College of Sports Medicine and the American Diabetes Association: Joint position statement. Diabetes Care, 33, e147–e167. Cowie, C. C., Rust, K. F., Ford, E. S., Eberhardt, M. S., Byrd-Holt, D. D., Li, C., et al. (2009). Full accounting of diabetes and pre-diabetes in the U.S. Population in 1988–1994 and 2005–2006. Diabetes Care, 32, 287–294. Desouza, C. V., Bolli, G. B., & Fonseca, V. (2010). Hypoglycemia, diabetes, and cardiovascular events. Diabetes Care, 33, 1389–1394. Gregg, E. W., Chen, H., Wagenknecht, L. E., Clark, J. E., Delahanty, L. M., Bantle, J., et al. (2012). Association of an intensive lifestyle intervention with remission of type 2 diabetes. JAMA: The Journal of the American Medical Association, 308, 2489–2496. Hamman, R. F., Wing, R. R., Edelstein, S. L., Lachin, J. M., Bray, G. A., Delahanty, L., et al. (2006). Effect of weight loss with lifestyle intervention on risk of diabetes. Diabetes Care, 29, 2102–2107. Inzucchi, S. E., Bergenstal, R. M., Buse, J. B., Diamant, M., Ferrannini, E., Nauck, M., et al. (2012). Management of hyperglycaemia in type 2 diabetes: A patient-centered approach. Position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia, 55, 1577–1596. Jakicic, J. M., Egan, C. M., Fabricatore, A. N., Gaussoin, S. A., Glasser, S. P., Hesson, L. A., et al. (2013). Four-year change in cardiorespiratory fitness and influence on glycemic control in adults with type 2 diabetes in a randomized trial: The Look AHEAD trial. Diabetes Care, 36, 1297–1303.
Knowler, W. C., Barrett-Connor, E., Fowler, S. E., Hamman, R. F., Lachin, J. M., Walker, E. A., et al. (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. The New England Journal of Medicine, 346, 393–403. Kodama, S., Tanaka, S., Heianza, Y., Fujihara, K., Horikawa, C., Shimano, H., et al. (2013). Association between physical activity and risk of all-cause mortality and cardiovascular disease in patients with diabetes: A meta-analysis. Diabetes Care, 36, 471–479. Morrato, E. H., Hill, J. O., Wyatt, H. R., Ghushchyan, V., & Sullivan, P. W. (2007). Physical activity in U.S. adults with diabetes and at risk for developing diabetes, 2003. Diabetes Care, 30, 203–209. Nicholas, J., Charlton, J., Dregan, A., & Gulliford, M. C. (2013). Recent HbA1c values and mortality risk in type 2 diabetes. Population-based case–control study. PLoS ONE, 8, e68008. Norris, S. L., Zhang, X., Avenell, A., Gregg, E., Brown, T., Schmid Christopher, H., et al. (2005). Long-term non-pharmacological weight loss interventions for adults with type 2 diabetes mellitus. Cochrane Database of Systematic Reviews Issue 2. Art. No.: CD004095. http://dx.doi.org/10.1002/14651858.CD004095.pub2. Skyler, J. S., Bergenstal, R., Bonow, R. O., Buse, J., Deedwania, P., Gale, E. A., et al. (2009). Intensive glycemic control and the prevention of cardiovascular events: Implications of the ACCORD, ADVANCE, and VA diabetes trials: A position statement of the American Diabetes Association and a scientific statement of the American College of Cardiology Foundation and the American Heart Association. Diabetes Care, 32, 187–192. Sluik, D., Buijsse, B., Muckelbauer, R., Kaaks, R., Teucher, B., Johnsen, N. F., et al. (2012). Physical activity and mortality in individuals with diabetes mellitus: A prospective study and meta-analysis. Archives of Internal Medicine, 172, 1285–1295. The Emerging Risk Factors Collaboration. (2010). Diabetes mellitus, fasting blood glucose concentration, and risk of vascular disease: A collaborative meta-analysis of 102 prospective studies. Lancet, 375, 2215–2222. The Look AHEAD Research Group. (2013). Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes. The New England Journal of Medicine, 369, 145–154. Wing, R. R., Hamman, R. F., Bray, G. A., Delahanty, L., Edelstein, S. L., Hill, J. O., et al. (2004). Achieving weight and activity goals among Diabetes Prevention Program lifestyle participants. Obesity Research, 12, 1426–1434.
April P. Carson Department of Epidemiology School of Public Health, University of Alabama at Birmingham Birmingham, AL, USA E-mail address: [email protected] Lovoria B. Williams College of Nursing Georgia Regents University, Augusta GA, USA Alethea N. Hill College of Nursing Adult Health Department, University of South Alabama Mobile, AL, USA
Contents lists available at ScienceDirect
Journal of Diabetes and Its Complications journal homepage: WWW.JDCJOURNAL.COM
Physical activity in diabetes: Is any better than none?
In the United States, 13% of adults have diabetes and an additional 30% are at high risk of developing diabetes (Cowie et al., 2009). Because diabetes increases the risk of vascular morbidity and mortality (The Emerging Risk Factors Collaboration, 2010), lifestyle modification and pharmacologic therapy are recommended (American Diabetes Association, 2013; Inzucchi et al., 2012) for clinical management and to prevent complications. In this issue of the Journal, Brown and colleagues (2014) investigated the association of lifestyle modification and pharmacologic therapy for type 2 diabetes mellitus (T2DM) with allcause and cardiovascular disease (CVD) mortality. Using data for adults ages ≥40 years, the authors investigated whether physical activity (PA) (defined as ≥1 PA weekly versus no PA weekly), pharmacologic therapy use (defined as treated with insulin or oral hypoglycemic medications versus not treated with insulin or oral hypoglycemic medications), and glycemic control (defined as HbA1c b 7.0% versus HbA1c ≥ 7%) were associated with risk of mortality. The authors classified participants with T2DM as 1) treated and controlled; 2) untreated and controlled; 3) treated and uncontrolled; 4) untreated and uncontrolled and further stratified their analyses by PA within each classification. The primary finding was that compared with individuals with T2DM who were physically active, treated, and controlled, individuals with T2DM who were physically inactive within each classification had an increased risk of all-cause and CVD mortality. Additionally, the mortality risk for individuals with T2DM who were physically active, treated, and controlled was similar to the mortality risk for those who did not have T2DM who were or were not physically active. The findings by Brown et al. suggest that PA as little as once weekly, which is less than the current PA recommendation, may yield health benefits for individuals with T2DM regardless of glycemic control or pharmacologic therapy use. The inverse association of PA with mortality risk among individuals with T2DM has been reported previously. Two meta-analyses reported PA decreased the risk of mortality among individuals with T2DM, with those in the highest PA category having a 40% lower risk of all-cause (Kodama et al., 2013; Sluik et al., 2012) and CVD mortality (Sluik et al., 2012) than those in the lowest PA category. Furthermore, a metaanalysis of the effect of PA on glycemic control among individuals with T2DM found that PA interventions, compared with no PA, resulted in lower HbA1c despite no significant weight change (Boulé, Haddad, Kenny, Wells, & Sigal, 2001). Individuals with T2DM are often overweight or obese, therefore many intervention studies have focused on weight reduction, with PA often included as part of the intervention, and have been mostly short-term (Norris et al., 2005). However, one multi-center randomized controlled trial, the Action for Health in Diabetes Study (Look AHEAD), evaluated the long-term effect of an Disclosures: Dr. Carson has received research support from Amgen, Inc.; Dr. Williams has no disclosures; and Dr. Hill is a scientific advisory board member for Sanofi-Aventis. 1056-8727/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jdiacomp.2013.10.012
intensive lifestyle intervention, which included 175 min of moderate intensity PA weekly as one of the components, among overweight and obese individuals with T2DM. After a median follow-up of 9.6 years, the intensive lifestyle intervention did not reduce CVD morbidity, all-cause mortality, or CVD mortality rates compared with the control group that received diabetes support and education (The Look AHEAD Research Group, 2013). Although the intervention did not result in any overall benefits for CVD morbidity or mortality, the intervention group did experience greater increases in PA (Jakicic et al., 2013), improvements in HbA1c and cardiovascular risk factors (The Look AHEAD Research Group, 2013), and the remission of diabetes (Gregg et al., 2012). Lifestyle interventions that include PA as one of the components have been shown to be effective for preventing T2DM. In the Diabetes Prevention Program, individuals at high risk for T2DM who received an intensive lifestyle intervention experienced 58% and 39% reductions in incident diabetes compared with the placebo and metformin groups, respectively (Knowler et al., 2002). Although 74% individuals in the intervention group met the PA goal at 6 months and 67% met the PA goal long-term (Wing et al., 2004), weight loss was the primary contributor to the reduced risk of diabetes overall. However, among individuals who did not meet the weight loss goal, those who met the PA goal had a lower risk of diabetes than those who did not meet the PA goal (Hamman et al., 2006). In the study by Brown et al., PA was associated with a lower risk of mortality among individuals with T2DM, even when glycemic control had been achieved. The appropriate HbA1c level for individuals with diabetes remains controversial, given randomized controlled trials that have reported no effect, and possible harm, associated with intensive glycemic control to HbA1c targets of b 6% or b6.5%, respectively, and mortality (Skyler et al., 2009). Current guidelines recommend a glycemic goal of HbA1c b 7% for many, but not all, adults with T2DM (American Diabetes Association, 2013). Brown and colleagues used this cut-point in their analyses, but this approach may obscure possible differential effects of PA across the spectrum of glycemic control (Calles-Escandon et al., 2010; Desouza, Bolli, & Fonseca, 2010), particularly for individuals with glycemic levels that are furthest from the recommended goal who have an increased risk of mortality (Nicholas, Charlton, Dregan, & Gulliford, 2013). The observational findings by Brown et al. suggest that PA, even as little as ≥ 1 time per week, may provide a mortality benefit for individuals with T2DM, but their study has several potential limitations. The authors did not use sampling weights to account for the survey sampling methods, so their findings are not representative of the US population and may be over- or underestimates of the PA and mortality association. Also, PA ≥ 1 time per week is a wide classification without an upper boundary, so it is possible that the association of PA with mortality among individuals with T2DM varies
258
Editorial / Journal of Diabetes and Its Complications 28 (2014) 257–258
according to the duration and frequency of PA. The current clinical recommendation for adults with T2DM is moderate to vigorous PA for 150 min weekly (Colberg et al., 2010), yet the majority do not attain this level of activity (Morrato, Hill, Wyatt, Ghushchyan, & Sullivan, 2007). The primary goal of treatment in diabetes focuses on achieving and maintaining optimal glycemic levels, but lifestyle modification, including PA, will remain central to the long-term clinical management of diabetes. It may be advantageous for individuals with T2DM to make incremental gains toward the recommended PA level because of its demonstrated glycemic benefits; however, further investigation of the glycemic and vascular effects of PA among individuals with T2DM is warranted.
References American Diabetes Association. (2013). Standards of medical care in diabetes—2013. Diabetes Care, 36, S11–S66. Boulé, N. G., Haddad, E., Kenny, G. P., Wells, G. A., & Sigal, R. J. (2001). Effects of exercise on glycemic control and body mass in type 2 diabetes mellitus: A meta-analysis of controlled clinical trials. JAMA: The Journal of the American Medical Association, 286, 1218–1227. Brown, R. E., Riddell, M. C., Macpherson, A. K., Canning, K. L., & Kuk, J. L. (2014). All-cause and cardiovascular mortality risk in U.S. adults with and without type 2 diabetes: Influence of physical activity, pharmacological treament and glycemic control. Journal of Diabetes and Its Complications, 28(3), 311–315. Calles-Escandon, J., Lovato, L. C., Simons-Morton, D. G., Kendall, D. M., Pop-Busui, R., Cohen, R. M., et al. (2010). Effect of intensive compared with standard glycemia treatment strategies on mortality by baseline subgroup characteristics: The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Diabetes Care, 33, 721–727. Colberg, S. R., Sigal, R. J., Fernhall, B., Regensteiner, J. G., Blissmer, B. J., Rubin, R. R., et al. (2010). Exercise and type 2 diabetes: The American College of Sports Medicine and the American Diabetes Association: Joint position statement. Diabetes Care, 33, e147–e167. Cowie, C. C., Rust, K. F., Ford, E. S., Eberhardt, M. S., Byrd-Holt, D. D., Li, C., et al. (2009). Full accounting of diabetes and pre-diabetes in the U.S. Population in 1988–1994 and 2005–2006. Diabetes Care, 32, 287–294. Desouza, C. V., Bolli, G. B., & Fonseca, V. (2010). Hypoglycemia, diabetes, and cardiovascular events. Diabetes Care, 33, 1389–1394. Gregg, E. W., Chen, H., Wagenknecht, L. E., Clark, J. E., Delahanty, L. M., Bantle, J., et al. (2012). Association of an intensive lifestyle intervention with remission of type 2 diabetes. JAMA: The Journal of the American Medical Association, 308, 2489–2496. Hamman, R. F., Wing, R. R., Edelstein, S. L., Lachin, J. M., Bray, G. A., Delahanty, L., et al. (2006). Effect of weight loss with lifestyle intervention on risk of diabetes. Diabetes Care, 29, 2102–2107. Inzucchi, S. E., Bergenstal, R. M., Buse, J. B., Diamant, M., Ferrannini, E., Nauck, M., et al. (2012). Management of hyperglycaemia in type 2 diabetes: A patient-centered approach. Position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia, 55, 1577–1596. Jakicic, J. M., Egan, C. M., Fabricatore, A. N., Gaussoin, S. A., Glasser, S. P., Hesson, L. A., et al. (2013). Four-year change in cardiorespiratory fitness and influence on glycemic control in adults with type 2 diabetes in a randomized trial: The Look AHEAD trial. Diabetes Care, 36, 1297–1303.
Knowler, W. C., Barrett-Connor, E., Fowler, S. E., Hamman, R. F., Lachin, J. M., Walker, E. A., et al. (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. The New England Journal of Medicine, 346, 393–403. Kodama, S., Tanaka, S., Heianza, Y., Fujihara, K., Horikawa, C., Shimano, H., et al. (2013). Association between physical activity and risk of all-cause mortality and cardiovascular disease in patients with diabetes: A meta-analysis. Diabetes Care, 36, 471–479. Morrato, E. H., Hill, J. O., Wyatt, H. R., Ghushchyan, V., & Sullivan, P. W. (2007). Physical activity in U.S. adults with diabetes and at risk for developing diabetes, 2003. Diabetes Care, 30, 203–209. Nicholas, J., Charlton, J., Dregan, A., & Gulliford, M. C. (2013). Recent HbA1c values and mortality risk in type 2 diabetes. Population-based case–control study. PLoS ONE, 8, e68008. Norris, S. L., Zhang, X., Avenell, A., Gregg, E., Brown, T., Schmid Christopher, H., et al. (2005). Long-term non-pharmacological weight loss interventions for adults with type 2 diabetes mellitus. Cochrane Database of Systematic Reviews Issue 2. Art. No.: CD004095. http://dx.doi.org/10.1002/14651858.CD004095.pub2. Skyler, J. S., Bergenstal, R., Bonow, R. O., Buse, J., Deedwania, P., Gale, E. A., et al. (2009). Intensive glycemic control and the prevention of cardiovascular events: Implications of the ACCORD, ADVANCE, and VA diabetes trials: A position statement of the American Diabetes Association and a scientific statement of the American College of Cardiology Foundation and the American Heart Association. Diabetes Care, 32, 187–192. Sluik, D., Buijsse, B., Muckelbauer, R., Kaaks, R., Teucher, B., Johnsen, N. F., et al. (2012). Physical activity and mortality in individuals with diabetes mellitus: A prospective study and meta-analysis. Archives of Internal Medicine, 172, 1285–1295. The Emerging Risk Factors Collaboration. (2010). Diabetes mellitus, fasting blood glucose concentration, and risk of vascular disease: A collaborative meta-analysis of 102 prospective studies. Lancet, 375, 2215–2222. The Look AHEAD Research Group. (2013). Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes. The New England Journal of Medicine, 369, 145–154. Wing, R. R., Hamman, R. F., Bray, G. A., Delahanty, L., Edelstein, S. L., Hill, J. O., et al. (2004). Achieving weight and activity goals among Diabetes Prevention Program lifestyle participants. Obesity Research, 12, 1426–1434.
April P. Carson Department of Epidemiology School of Public Health, University of Alabama at Birmingham Birmingham, AL, USA E-mail address: [email protected] Lovoria B. Williams College of Nursing Georgia Regents University, Augusta GA, USA Alethea N. Hill College of Nursing Adult Health Department, University of South Alabama Mobile, AL, USA
