Tissue Sodium Content and Arterial Hypertension in Obese Adolescents.
Roth S., Markó L., Birukov A., Hennemuth A., Kühnen P., Jones A., Ghorbani N., Linz P., Müller DN., Wiegand S., Berger F., Kuehne T., Kelm M.
Early-onset obesity is known to culminate in type 2 diabetes, arterial hypertension and subsequent cardiovascular disease. The role of sodium (Na+) homeostasis in this process is incompletely understood, yet correlations between Na+ accumulation and hypertension have been observed in adults. We aimed to investigate these associations in adolescents. A cohort of 32 adolescents (13-17 years), comprising 20 obese patients, of whom 11 were hypertensive, as well as 12 age-matched controls, underwent 23Na-MRI of the left lower leg with a standard clinical 3T scanner. Median triceps surae muscle Na+ content in hypertensive obese (11.95 mmol/L [interquartile range 11.62-13.66]) was significantly lower than in normotensive obese (13.63 mmol/L [12.97-17.64]; p = 0.043) or controls (15.37 mmol/L [14.12-16.08]; p = 0.012). No significant differences were found between normotensive obese and controls. Skin Na+ content in hypertensive obese (13.33 mmol/L [11.53-14.22] did not differ to normotensive obese (14.12 mmol/L [13.15-15.83]) or controls (11.48 mmol/L [10.48-12.80]), whereas normotensive obese had higher values compared to controls (p = 0.004). Arterial hypertension in obese adolescents is associated with low muscle Na+ content. These findings suggest an early dysregulation of Na+ homeostasis in cardiometabolic disease. Further research is needed to determine whether this association is causal and how it evolves in the transition to adulthood.