Heritability of Cold and Heat Patterns: A Twin Study

Abstract

In traditional East Asian medicine, cold-heat patterns have been widely used in the diagnosis and treatment of patients suffering from various diseases. The present study aimed to estimate the heritability of cold-heat patterns. Trained interviewers administered a cold-heat pattern questionnaire to 1,753 twins (mean age = 19.1 ± 3.1 years) recruited throughout South Korea. Correlations for the cold pattern (CP) were 0.42 (95% CI [0.28, 0.54]) for monozygotic (MZ) males, 0.16 (95% CI [-0.08, 0.39]) for dizygotic (DZ) males, 0.40 (95% CI [0.30, 0.49]) for MZ females, 0.30 (95% CI [0.12, 0.45]) for DZ females, and 0.07 (95% CI [-0.11, 0.25]) for opposite-sex DZ twins. The corresponding twin correlations for the heat pattern (HP) were 0.38 (95% CI [0.24, 0.51]), -0.22 (95% CI [-0.43, 0.02]), 0.34 (95% CI [0.24, 0.43]), 0.21 (95% CI [0.03, 0.37]), and 0.08 (95% CI [-0.10, 0.26]), respectively. These patterns of twin correlations suggested significant genetic effects on the HP and the CP. Model-fitting analysis revealed that heritability estimates in both sexes were 40% (95% CI [38, 42]) for the CP and 33% (95% CI [25, 42]) for the HP, with the remaining variances attributable to unique environmental variances. These estimates did not vary significantly with age during adolescence and young adulthood.

Etiologies of the Relationships Among Body Mass Index and Cold-Heat Patterns: A Twin Study

“…Figure 1 presents , respectively. These estimates were very close to the estimates found in our previous studies based on univariate biometrical models (Hur et al, 2018).…”

“…In support of the findings from twin studies, gene identification studies have successfully detected several FTO gene variants related to BMI (e.g., Qi et al, 2014). Using the sample employed in the present study, we recently showed that the CP and the HP are heritable traits, with heritability estimates being 40% (95% CI [38,42] [25,42) for the latter (Hur et al, 2018). As with many other complex traits, shared environmental influences on the CP and the HP were negligible, and environmental factors that influenced the CP and the HP were mainly individual specific.…”

“…To determine the causes of covariance among BMI, the HP, and the CP, twin correlations and cross-twin, crosstrait correlations for MZ and DZ twins were computed and model-fitting analyses were carried out. As our previous study has shown no significant sex or age differences in genetic and environmental influences on the HP and the CP (Hur et al, 2018), prior to twin correlation and modelfitting analyses, we combined both sexes and corrected the data for age, age 2 , sex, and age × sex, using a regression method (McGue & Bouchard, 1984). A trivariate Cholesky model (Neale & Cardon, 1992) was applied to the data.…”

“…The sample consisted of 1,752 (1,047 monozygotic (MZ) and 705 dizygotic (DZ)) twins (mean age = 19.1 yrs; SD of age = 3.1 yrs; range = 12-29 yrs) drawn from the South Korean Twin Registry (Hur et al, 2013). A detailed description of the present sample can be found in Hur et al (2013Hur et al ( , 2018.…”

Autoregressive Cross-Lagged Modeling of The Longitudinal Relationship Between Sub-Health and Cold Hypersensitivity

“…The cold pattern (CP) is characterized by a preference for warm temperature, intolerance of cold, hypothermia, paleness, diarrhea, peripheral chills, and spasms (8). Especially, cold hypersensitivity in the hands and feet (CHHF) is a condition in which affected individuals feel excessively cold at low temperatures because of spastic peripheral vasoconstriction.…”