Height and atrial fibrillation
SEATTLE, WASHINGTON. In our very first LAF Survey (February 2001), it was noted that male afibbers tended to be significantly taller (183 cm or 6 ft) than the average US male (178 cm or 5 ft 10 in). Corresponding figures for female afibbers and average US females were 168 cm (5 ft 6 in) and 164 cm (5 ft 4.6 in). LAF Survey 11 (November 2005) was carried out in cooperation with Patrick Chambers, MD to follow up on this finding. The results are discussed in Dr. Chambers' report LAF versus AF: Shape Matters and confirmed the significant difference in height between lone afibbers, both male and female, and the population average. Dr. Chambers' work was subsequently published in Medical Hypotheses (Patrick W. Chambers, Lone atrial fibrillation: Pathologic or not? Medical Hypotheses, Vol. 68, No. 2, 2007, pp. 281-87).

Now a group of researchers from the University of Washington confirms that taller men and women are more likely to have, or develop, atrial fibrillation (AF) than are men and women of average height. Their study included 5860 men and women enrolled in the Cardiovascular Health Study, a cohort study of older US adults followed for a median of 13.6 years (women) or 10.3 years (men), of which 66% had hypertension, and 19% had cardiovascular disease. At baseline there were 157 (2.7%) cases of AF amongst the 5860 participants. During follow-up of 5117 participants, an additional 684 women and 568 men developed AF for a total incidence of 24.5%.

After adjusting for a significant number of possible confounders, the researchers found a 26% increased risk of developing AF for each 10 cm (4 in) of height above normal. The increased risk for women for 10 cm increase was 32%. Left atrial dimension, commonly thought to be the primary mediator of height-induced AF, was not significantly correlated with height.

The researchers speculate that the association between height and risk of AF may be genetically determined as two AF-associated genes, PITX2 and ZFHX3, are also associated with growth pathways. They conclude that independent of gender increased height is significantly associated with the risk of AF.

Rosenberg, MA, et al. The impact of height on the risk of atrial fibrillation. European Heart Journal, Vol. 33, 2012, pp. 2709-17

Editor's comment: It is gratifying to see our work confirmed, although it would have been even better if the authors had acknowledged Dr. Chambers' earlier work. The authors made a statement that really caught my attention – "A recent study[1] found that increased birth weight was significantly associated with the development of AF in women." Combining this finding with the finding in our LAF Survey 14, which showed that the only variable predicting whether or not participants had been able to find a way, other than ablation or surgery, to eliminate or materially reduce their AF burden was birth weight. A higher birth weight was associated with a complete inability to benefit from natural approaches to AF reduction/elimination. If higher birth weight is genetically associated with increased risk of developing AF, would it not make sense that high birth weight individuals would have more difficulty reducing their AF burden by natural means?

[1] Conen, D, et al. Birth weight is a significant risk factor for incident atrial fibrillation. Circulation, Vol. 122, 2010, pp. 764-70