In the Journals

Household income drop over 6 years may raise long-term CVD risk

Scott D. Solomon

In the U.S., changes in household income were significantly associated with subsequent incident CVD, with a strong link between drop in income and risk for CVD, according to a study published in JAMA Cardiology.

Individuals who experienced a household income drop of more than 50% during a 6-year period had a significantly higher risk for incident CVD, defined as MI, fatal CHD, HF or stroke, during a mean 17 years of follow-up (HR = 1.17; 95% CI, 1.03-1.32) compared with those whose income remained the same.

Moreover, individuals who received an income rise of more than 50% during a 6-year period had a significantly lower risk for incident CVD during the same 17-year follow-up (HR = 0.86; 95% CI, 0.77-0.96) compared with those whose income did not change.

Plausible mechanisms

“There are several plausible mechanisms that can explain the observed association between income changes and risk of CVD,” Scott D. Solomon, MD, Edward D. Frohlich Distinguished Chair and professor of medicine at Harvard Medical School and senior physician at Brigham and Women’s Hospital, and colleagues wrote. “An unanticipated drop in income may induce changes in health behaviors. For example, income loss has been associated with a shift toward consumption of less healthy foods, eg, foods that are more energy dense and yield more calories for a given price. Income drops may also result in loss of health insurance coverage, although we did not observe that in this study population.”

In other findings, following a fully adjusted analysis, individuals who experienced an income drop had elevated risk for MI/fatal CHD (HR = 1.28; 95% CI, 1.06-1.55) and definite or probable stroke (HR = 1.32; 95% CI, 1.05-1.67), and those who had a rise in income had a significantly lower risk for incident HF (HR = 0.83; 95% CI, 0.72-0.96) compared with individuals whose income did not change.

“Lower incomes may be associated with depression, which increases the risk of coronary artery disease,” the researchers wrote. “We attempted to elucidate some of these mechanisms by adjusting for health insurance status and health behaviors after income change. However, our HRs did not change significantly from the original model; hence, there must be other factors, beyond health behaviors and health insurance coverage, that account for these associations.”

In addition, researchers observed that the effect of an income drop on CVD risk was more pronounced in white individuals compared with black individuals (white participants, HR = 1.28; 95% CI, 1.11-1.48; black participants, HR = 1.01; 95% CI, 0.79-1.29). Also, it was noted that an income rise was more likely to lower risk for incident CVD among women compared with men (women, HR = 0.74; 95% CI, 0.63-0.87; men, HR = 1.01; 95% CI, 0.86-1.18).

Societal problem

According to the study, 10% of participants had an income drop, with mean household incomes falling from $40,516 to $14,655; 70% of participants had household income unchanged ($43,897 to $43,057); and 20% experienced an income rise, with mean incomes increasing from $26,099 to $53,347.

Using data obtained through the ARIC study, researchers analyzed income changes during a 6-year period, between the first visit (1987 to 1989) and the third visit (1993 to 1995), among 8,989 participants (mean age, 53 years; 20% black; 43% men) and their effect on incident CVD, MI, fatal CHD, HF or stroke during a mean 17-year follow-up.

“The broader question this article asks us is how we as physicians should respond to a societal problem that leads to illness,” Edward P. Havranek, MD, director of medicine at Denver Health and professor of medicine at the University of Colorado School of Medicine, wrote in a related editorial. “Few physicians question our responsibility to advocate for public efforts to decrease smoking rates, but many would question a responsibility to advocate for greater economic security. However, the choice between plunging into political discussions and avoiding the discussions altogether is a false one. We as a profession have a responsibility to promote full understanding of the health effects of the social structure we as a society have chosen. Results, such as those put forward by Wang et al, are clearly a step in that direction.” – by Scott Buzby

Disclosures: Solomon reports he received grants from Alnylam, Amgen, AstraZeneca, Bellerophon, Bayer, Bristol-Myers Squibb, Celladon, Cytokinetics, Eidos, Gilead, GlaxoSmithKline, Ionis, Lone Star Heart, Mesoblast, MyoKardia, NIH/NHLBI, Novartis, Sanofi Pasteur and Theracos and personal fees from Akros, Alnylam, Amgen, AOBiome, Arena, AstraZeneca, Bayer, Bristol-Myers Squibb, Cardiac Dimensions, Cardior, Cardurion, Corvia, Cytokinetics, Daiichi Sankyo, Gilead, GlaxoSmithKline, Ironwood, Janssen, Merck, MyoKardia, Novartis, Quantum Genetics, Roche, Takeda, Theracos and Tenaya. Havranek reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Scott D. Solomon

In the U.S., changes in household income were significantly associated with subsequent incident CVD, with a strong link between drop in income and risk for CVD, according to a study published in JAMA Cardiology.

Individuals who experienced a household income drop of more than 50% during a 6-year period had a significantly higher risk for incident CVD, defined as MI, fatal CHD, HF or stroke, during a mean 17 years of follow-up (HR = 1.17; 95% CI, 1.03-1.32) compared with those whose income remained the same.

Moreover, individuals who received an income rise of more than 50% during a 6-year period had a significantly lower risk for incident CVD during the same 17-year follow-up (HR = 0.86; 95% CI, 0.77-0.96) compared with those whose income did not change.

Plausible mechanisms

“There are several plausible mechanisms that can explain the observed association between income changes and risk of CVD,” Scott D. Solomon, MD, Edward D. Frohlich Distinguished Chair and professor of medicine at Harvard Medical School and senior physician at Brigham and Women’s Hospital, and colleagues wrote. “An unanticipated drop in income may induce changes in health behaviors. For example, income loss has been associated with a shift toward consumption of less healthy foods, eg, foods that are more energy dense and yield more calories for a given price. Income drops may also result in loss of health insurance coverage, although we did not observe that in this study population.”

In other findings, following a fully adjusted analysis, individuals who experienced an income drop had elevated risk for MI/fatal CHD (HR = 1.28; 95% CI, 1.06-1.55) and definite or probable stroke (HR = 1.32; 95% CI, 1.05-1.67), and those who had a rise in income had a significantly lower risk for incident HF (HR = 0.83; 95% CI, 0.72-0.96) compared with individuals whose income did not change.

“Lower incomes may be associated with depression, which increases the risk of coronary artery disease,” the researchers wrote. “We attempted to elucidate some of these mechanisms by adjusting for health insurance status and health behaviors after income change. However, our HRs did not change significantly from the original model; hence, there must be other factors, beyond health behaviors and health insurance coverage, that account for these associations.”

In addition, researchers observed that the effect of an income drop on CVD risk was more pronounced in white individuals compared with black individuals (white participants, HR = 1.28; 95% CI, 1.11-1.48; black participants, HR = 1.01; 95% CI, 0.79-1.29). Also, it was noted that an income rise was more likely to lower risk for incident CVD among women compared with men (women, HR = 0.74; 95% CI, 0.63-0.87; men, HR = 1.01; 95% CI, 0.86-1.18).

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Societal problem

According to the study, 10% of participants had an income drop, with mean household incomes falling from $40,516 to $14,655; 70% of participants had household income unchanged ($43,897 to $43,057); and 20% experienced an income rise, with mean incomes increasing from $26,099 to $53,347.

Using data obtained through the ARIC study, researchers analyzed income changes during a 6-year period, between the first visit (1987 to 1989) and the third visit (1993 to 1995), among 8,989 participants (mean age, 53 years; 20% black; 43% men) and their effect on incident CVD, MI, fatal CHD, HF or stroke during a mean 17-year follow-up.

“The broader question this article asks us is how we as physicians should respond to a societal problem that leads to illness,” Edward P. Havranek, MD, director of medicine at Denver Health and professor of medicine at the University of Colorado School of Medicine, wrote in a related editorial. “Few physicians question our responsibility to advocate for public efforts to decrease smoking rates, but many would question a responsibility to advocate for greater economic security. However, the choice between plunging into political discussions and avoiding the discussions altogether is a false one. We as a profession have a responsibility to promote full understanding of the health effects of the social structure we as a society have chosen. Results, such as those put forward by Wang et al, are clearly a step in that direction.” – by Scott Buzby

Disclosures: Solomon reports he received grants from Alnylam, Amgen, AstraZeneca, Bellerophon, Bayer, Bristol-Myers Squibb, Celladon, Cytokinetics, Eidos, Gilead, GlaxoSmithKline, Ionis, Lone Star Heart, Mesoblast, MyoKardia, NIH/NHLBI, Novartis, Sanofi Pasteur and Theracos and personal fees from Akros, Alnylam, Amgen, AOBiome, Arena, AstraZeneca, Bayer, Bristol-Myers Squibb, Cardiac Dimensions, Cardior, Cardurion, Corvia, Cytokinetics, Daiichi Sankyo, Gilead, GlaxoSmithKline, Ironwood, Janssen, Merck, MyoKardia, Novartis, Quantum Genetics, Roche, Takeda, Theracos and Tenaya. Havranek reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.