Adolescent Hyperglycemia, Insulin Resistance Drive Early Cardiac Structural Changes, Novel Cohort Study Finds
Persistent hyperglycemia between ages 17 and 24 tripled the risk of left ventricular hypertrophy and did so 5 times faster among young women, a new study found.
"We observed that high blood sugar may aggressively damage females’ hearts five times faster than males’; therefore, special attention should be paid to girls in terms of prevention."
Persistently elevated blood glucose and insulin resistance (IR) during adolescence and early adulthood significantly increase the risk of structural and functional heart damage, according to a new study published in Diabetes Care. Researchers round that young women were at significantly greater risk of heart failure than young men and the largest association for the effect of IR on cardiac structure was with fat mass.1
Among 1,595 adolescents followed from age 17 to 24 years, a persistent fasting blood sugar (FBG) of 101.7 mg/dL or greater was associated with a 46% higher risk of left ventricular hypertrophy (LVH); at the more lenient cutpoint of 110 mg/dL, the risk was tripled, according to study authors. The prevalence of LVH increased threefold, from 2.4% at age 17 to 7.1% at age 24, and heart dysfunction rose from 9.2% to 15.8% over the same period.1
The research was led by Andrew Agbaje, MD, MPH, PhD, associate professor of clinical epidemiology and child health at the University of Eastern Finland, in collaboration with researchers from the US, Sweden, and the UK.1
The impact of youth-onset type 2 diabetes on heightened risk for complications by midlife is well recognized, including the effect of IR and dysglycemia on cardiac structure in adults.2 There is no research, however, that has evaluated the earliest manifestations of elevated blood glucose and IR on cardiac structure and function, largely a result of "the scarcity of repeated echocardiography assessments of the heart in a large population of healthy youth," Agbaje noted in a statement.3 They identify their study, which followed adolescents from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) cohort, as the "largest and longest follow-up of glucose concentration and repeated echocardiography in a healthy young population worldwide."3
Agbaje et al reported that adolescents with FBG at the prediabetes level faced substantially greater heart risks as they transitioned into adulthood. Overall, 6.2% of adolescents at age 17 had FBG of 101.7 mg/dL or greater, which increased nearly 5-fold to 26.9% by age 24 years. Just 1.1% of the cohort at age 17 had a FBG level of 110 mg/dL, but that prevalence increased by 5 times as well, to 5.6%.1
Persistent insulin resistance was associated with a 10% increased risk of premature and worsening heart damage. During the 7 years between study visits at age 17 and 24, increased glucose levels contributed 0.57 g/m².⁷ to cardiac mass in young women compared to an increase of only 0.11 g/m².⁷ in young men, according to the study.1 "Surprisingly, we observed that high blood sugar may aggressively damage females’ hearts five times faster than males’; therefore, special attention should be paid to girls in terms of prevention," Agbaje added.3
The study also highlighted the vicious cycle between insulin resistance and fat mass accumulation. "Worsening insulin resistance and increased fat mass have a bidirectional reinforcing vicious cycle. In the new study, we observed that two-thirds of the effect of insulin resistance on excessive heart enlargement was explained by increased total body fat," Agbaje noted.3
"Earlier results from the same cohort indicate that late adolescence is a critical period in the evolution of cardiometabolic diseases. The current findings further confirm that even healthy-looking adolescents and young adults who are mostly normal weight may be on a path towards cardiovascular diseases, if they have high blood glucose and insulin resistance," Agbaje emphasized.3
Researchers included adolescents from the ALSPAC who had measures of FPG and insulin levels and echocardiography of left ventricular mass at clinic visits at ages 17 and 24, according to the study.1
Participants’ fasting blood glucose and insulin levels were measured at ages 17 and 24, alongside echocardiographic evaluations of cardiac structure and function. Additional repeated measures included lipid profiles hsCRP blood pressure, and body composition via dual-energy X-ray absorptiometry. Investigators used multivariable adjustment for socioeconomic status, family history of cardiovascular disease, smoking status, and objectively measured sedentary behavior and physical activity.1
The rapid rise in prediabetes rates and the accompanying cardiovascular changes highlight the urgent need for early prevention strategies focused on lifestyle and diet, particularly as adolescents gain independence from family structures that may have previously supported healthier habits.
