Background:
It is clinically widely overlooked that many patients with
Marfan- (MFS) or Loeys-Dietz-Syndrome (LDS) are obese. While anthropometric
routine parameters are not very suitable, the modern Bioelectrical Impedance
Analysis (BIA) seems superior for the acquisition of reliable noninvasive
assessment of body composition of patients. The aim of the study was to assess
the body composition of patients with MFS/LDS by BIA in order to detect occult
obesity, which may be a risk marker for aortic or vascular complications.
Methods:
In this exploratory cross-sectional study, 50 patients (66%
female; mean age: 37.7
11.7 [range: 17–64] years) with a molecular
genetic (n = 45; 90%) or clinical (n = 5; 10%) proven diagnosis of MFS or LDS
were enrolled between June 2020 and February 2022. All BIA-measurements were
performed with the Multifrequence-Impedance-Analyzer Nutriguard-MS (Data Input,
Poecking, Germany).
Results:
The MFS/LDS collective was significantly
different from an age-, sex-, and BMI-adjusted control in terms of body fat,
percent cellularity, body cell mass, extra cellular mass/body cell mass index,
and phase angle (all
p
0.05). The mean BIA-measured bodyfat
was 31.7
8.7% [range: 9.5–53.5%], while the mean calculated BMI of the
included patients was 23.0
4.8 kg/
[range: 15.2–41.9 kg/
].
Therefore, using the obesity cut-off values for the body fat percentage of 25%
in men and 35% in women, the BIA classifies as many as 28 patients (56.0%) as
obese. In contrast only 12 patients (24.0%) were pre-obese, respectively 3
(6.0%) obese by BMI. The significant difference (
p
0.001) had an
accordance of 42.7%. Overall, 15 patients (13 MFS; 2 LDS) had previous aortic
surgery (n = 14) and/or interventional treatment (n = 2) for aortic complications
(aneurysm, aortic dissection). 11 out of these 15 (73.3%) were currently
classified as obese by BIA.
Conclusions:
The fact that many patients
with MFS or LDS are obese is widely unknown, although obesity may be associated
with impaired vascular endothelial function and an increased risk of
cardiovascular complications. Also, in patients with MFS/LDS, BIA allows a
reliable assessment of the body composition beyond the normal anthropometric
parameters, such as BMI. In the future, BIA-data possibly may be of particular
importance for the assessment of the vascular risk of MFS/LDS patients, besides
the aortic diameters.