Key findings from our young adult lipid study include the relative similarity of Furman students’ lipid data as well as healthier lipid values overall when compared with the NHANES database. Our evidence suggests that there is no clear significant difference by race, socioeconomic status, or financial need category. Our data also shows some significant differences by sex as expected as well as some healthier lipid values in HDL-C, VLDL-C, and triglycerides in African-Americans which have been described in other studies. Although African-Americans also demonstrated greater percentages of athletic involvement overall, these were independent of healthier cholesterol values (with approximately 18% AA students with university-sponsored athletic team involvement versus 7.3% total student involvement, per de-identified student enrollment records). Our study suggests that most college-age students, as expected, may likely demonstrate normal lipid values throughout adolescence. A small fraction of our database showed evidence of hypercholesterolemia per NHLBI guidelines 12, suggesting that a fraction of otherwise healthy and high-functioning young adults are at risk for developing CVD sooner than the typical college graduate. Our study’s clinical significance exists primarily in the identification of cholesterol values outside of the acceptable risk range in all categories, including LDL-C, Total Cholesterol, and Triglycerides, for a liberal arts college student population. Our study’s primary research contribution is the demographic association of certain minority statuses with changes in cholesterol values, wherein African-Americans demonstrated healthier cholesterol values in VLDL-C, triglyceride, and HDL-C subcategories. Another primary research contribution is the surprising discovery that SES status has much less impact on lipid values for our study than many adult studies suggest as above. Finally, future research may benefit profoundly from the association of university enrollment with improved lipid values, and this information may be useful to clinicians when considering risk factors for future CVD in their youth patients.
According to the American Heart Association, abnormal lipid values affect 1 in 5 adolescents and screening values for dyslipidemia (>95%) include TC >200 mg/dL, TG > 130 mg/dL, HDL-C < 40 mg/dL, LDL-C > 130 mg/dL, and Non-HDL-C > 145 mg/dL 37. With regard to the higher HDL-C values in Furman college African-American students, a similar Multiple Risk Factor Intervention Trial has also shown African-American males demonstrating on average 10 mg/dL higher HDL-C levels and an inverse relationship between HDL-C and SES status in African-American men vs white men (while SES status and HDL-C was directly correlated in white men) 13. While more research is needed in this area to confirm these findings, this may give support to the concept that African-American students who are physically active and subsequently more health-conscious are also more likely to avoid CVD than other less active ethnic or minority individuals. Regardless, additional research on which socioeconomic factors contribute to these perplexing trends in cholesterol health disparities worldwide is clearly indicated due to these findings in the current population. This should also raise awareness of the possibility of different lipid thresholds existing for various ethnicities; in other words, we cannot disprove a continued higher risk for clinical CVD at an early age for certain minority populations despite normal youth lipid screening test results.
Potential confounders for the data include variations in age (although minor) as all students were between 18-24 per original data from Furman Health Science department collections. The significance of some data may be secondary to small or large sample sizes in comparison with the total database, especially for medium need students in Table 1 (compared with other need categories with much larger samples). When comparing Furman data to national data, possible confounding variables include availability of wellness resources and education. Students enrolled at a private liberal arts school likely exhibit a component of wellness via self-selection to education programs including Furman that encourage a healthy and wellness-focused predisposition that may be less available in other populations.
Previous studies in cholesterol research demonstrate that low socioeconomic status (SES) and minority ethnicity are established risk factors for poor cholesterol health, which is impacted by both quantifiable and nonquantifiable determinants 14,15,16,17,18,19,20. Quantifiable risk factors are cholesterol values (including non-fasting triglyceride levels), hemoglobin A1c levels, smoke exposure 21, family history of stroke, diabetes, or obesity (specifically for African-American youths) 22, and [from highest to lowest odds ratios] single-living, non-white status, low income, and low education 23. Nonquantifiable risk factors are much broader and include language barriers and lack of healthcare access4, low and medium educational levels16, having a negative affect in familial interactions24, and poor health promotion behaviors including low knowledge of personal risk indicators for CVD 25,26. Minority status also is recognized as an independent risk factor for high blood pressure, heart attack and stroke27, lower rates of moderate exercise28, decreased cholesterol medication adherence29, lower likelihood of prior lipid screening among children with stroke[s]30, increased LDL-C, BP, and A1c among veterans31, and even increased all-cause mortality 32.
One limitation of our study may exist as more Caucasian students attend Furman than other average university populations; however, our large sample size allowed us to include students from diverse socioeconomic and minority backgrounds with strong statistical associations within each group and lipid subcategory. We also recognize some discrepancies exist inherent within comparisons between the NHANES data and our Furman University data, including the assumption that our high financial need category in Furman’s database is comparable to the NHANES low income category (and vice versa). However, we have included the various salaries for each group in our data tables below to avoid confusion in SES classification. A strength of our study is the detailed comparison of various types of students within the Furman database such as athlete and non-athlete status and the inclusion of several levels of socioeconomic status, which is often absent from similar lipid studies. Another strength is the comparison of our original data with an age-matched control database from NHANES, which allows for unique verification of cholesterol trends between distinct groups of youths. As above, other confounders/limitations potentially include variations in age and the lack of further demographic data to delineate how Furman students differ from the NHANES data including access to wellness curriculum and physical activity resources which are essential to maintain healthy biomarkers throughout young adulthood.
As described above, adult-onset cardiovascular disease continues to be identified (and treated) by clinicians worldwide using routine lipid screening protocols in adolescence and beyond. However, even with current technological advancements in cardiovascular imaging and updated lipid screening recommendations, less is known about how to identify a younger and more insidious version of lipid disease that exists with little to no clinical symptoms in adolescence. To complicate future research in lipid screening even further, other lipid study efforts demonstrate that several nonnumeric factors including psychosocial, social, and family of origin characteristics are also related to lipid health, and that healthy behaviors in these areas maintain some degree of lifelong protection from CVD 33. Current literature seems to lack enough well-described data or demographic associations to fully circumscribe the bulk of youth lipid disease as compared with CVD in adult populations. In accordance with the American Academy of Pediatrics and National Heart Lung and Blood Institute guidelines as above, we encourage careful consideration of lipid screening for any child during their preadolescent (ages 9-11) and adolescent (ages 17-21) primary care/health maintenance encounters, especially those with significant family history of lipid disorders or other comorbidities including obesity or high blood pressure. Otherwise delayed diagnosis and treatment is overdue when initiated at age 35 or even beyond (per USPSTF guidelines) 34, and CVD morbidity and mortality will continue to impact these individuals for many years unless change is implemented.
Other researchers have shown that African-American ethnicity is associated with healthier lipid values, most notably the Bogalusa study demonstrating higher HDL-C and lower triglycerides in African-Americans vs whites 35. A more recent study by Sumner et al also demonstrated similar findings and also mentions that African-Americans have higher rates of cardiovascular disease and diabetes but paradoxically are diagnosed less often with metabolic syndrome. This is likely due to the requirement that low HDL-C and high triglycerides make up two-fifths of the criteria for diagnosing metabolic syndrome (along with central obesity, hypertension, and fasting hyperglycemia), which African-Americans are less likely to have despite worse disease outcomes 36. Thus the data our study unearthed likely represents a similar relationship and does not necessarily represent cardioprotective effects from seemingly healthier lipid values, although more research in the age group from our study is needed to verify these trends as compared with adults.
Finally, our study findings concur with the need for broader cholesterol screening as described above, as literature previously has also suggested that further advances in treating cardiovascular disease via lipid management may be realized better with broader insurance coverage, simplified cardiac risk assessments and improved access to culturally and linguistically appropriate healthcare 4. In addition to our findings of healthier lipid values in the college database versus the national sample database, there may be an inherent association between higher SES and educational attainment, as even beginning university students are often expected to pay high tuition rates. As described in Kenik et al, these and other similar healthy lifestyle practices as well as routine health maintenance visits likely hold the greatest promise for improving cardiovascular disease screening and treatment for vulnerable populations.