Increasing Income Mobility Associated with Health Tradeoffs

Gregory Miller, PhD

A new review of data is shedding light on the specific impact higher socioeconomic status can have on cardiometabolic health throughout a person’s lifetime.

While most studies link increased personal wealth to improved outcomes, the new prospective study found upward income mobility was not always beneficial for cardiometabolic health, even when it improved economic standing and mental health.

Led by Gregory Miller, PhD, of Northwestern University, and colleagues from the University of Georgia, the study examined data from 2 multi-decade studies—National Longitudinal Study of Adolescent Health (Add Health) and the Midlife in the United States Study (MIDUS). Investigators identified cohorts of 7542 (Add Health) and 1877 (MIDUS) patients to include in their analysis, which was designed to assess the impact of upward income mobility on overall health status.

For the purpose of their analysis, investigators defined income mobility as the meaning higher or lower income in adulthood relative to childhood. Using this as a guide, investigators created 4 specific groups based on a participant’s family income during childhood and adulthood—consistent lifecourse disadvantage, upward mobility, downward mobility, and consistent lifecourse advantage.

Investigators determined health status in adulthood based on the presence of perceived stress, depressive symptoms, and metabolic syndrome. Of note, perceived stress was measured through Cohen’s scale in both studies and CES-D scale was used to assess depression in both studies.

The primary outcome of the analysis was the diagnosis of metabolic syndrome, as defined by the International Diabetes Federation (IDF). Investigators also performed sensitivity analyses to assess the number of signs for which a participant exceed the IDF threshold. All models used by investigators were adjusted for age, sex, and race/ethnicity.

Results of the investigators’ analysis ultimately revealed evidence of a tradeoff. While upward income mobility was linked to lower perceived stress and fewer depressive symptoms but also to higher rates of metabolic syndrome. Results also indicated downward income mobility was associated with worse outcomes across all health indicators included in the study.

Investigators highlighted participants classified as upwardly mobile were less likely to experience significant depression compared to those with consistent disadvantage (18% vs 23% in Add Health; 12% vs 29% in MIDUS). Additionally, investigators pointed out upwardly double patients were 21%-27% more likely to show a tradeoff paternities compared to the consistently advantaged (Add Health, RR 1.21; 95% CI, 1.06-1.37; MIDUS: RR 1.27; 95% CI, 1.07-1.52) and that risk increased to 34-36% more likely compared to the consistently disadvantaged (Add Health, RR 1.34; 95% CI, 1.01-1.77; MIDUS, RR 1.36; 95% CI, 1.00-1.84).

Investigators noted multiple limitations within their study. Limitations included using a coarse method to assess lifecourse socioeconomic conditions, an absence of health measurements from childhood in both studies, and a lack of clarity surrounding how bored or narrow the apparent mobility-health tradeoff is.

Despite the limitations of their analyses, investigators purport the results of the study indicate upward income mobility is not always associated with improved cardiometabolic health and that psychological well-being and cardiometabolic health are not always aligned.

This study, “Youth Who Achieve Upward Socioeconomic Mobility Display Lower Psychological Distress But Higher Metabolic Syndrome Rates as Adults: Prospective Evidence from the National Study of Adolescent Health and The Midlife in the United States Study,” was published in JAHA.