CLOCK and Hypertension: Furthermore, Sookoian et al. (2010) demonstrated a significant interaction between polymorphisms in the promoter region of the serotonin transporter gene and common variants of the CLOCK gene affecting diastolic, systolic, and arterial hypertension, as well as plasma triglyceride levels in rotating shift workers, who are particularly susceptible to developing metabolic abnormalities and a non-dipping pattern of BP [25].