['With the advent of ambulatory blood pressure monitoring has come the awareness that blood pressure (BP) normally drops, or "dips," at night by roughly 10%. A number of pathological conditions have been associated with the nondipping of nocturnal BP. In general, researchers have looked at dipping in neurological and cardiovascular disorders. We examined the extent to which nocturnal nondipping might be influenced by relatively gross measures of social environment.', 'This study examined 78 healthy adults and adults with mild hypertension who were not currently receiving medication, aged 25 to 52 years (mean age = 38.2). Forty-two participants self-identified as black and 36 identified as white.', 'Age, body mass index, apnea-hypopnea index, screening BP, ethnicity, and socioeconomic status (SES) were significantly associated with nocturnal BP dipping, accounting for 41% of the variance in dipping (F[6,51] = 5.473, p <.001). When SES was entered on the last step of a hierarchical regression analysis, it independently accounted for 8% of the variance in dipping, even after accounting for ethnicity, such that the lower the SES, the more the nondipping.'] Is socioeconomic status associated with nocturnal blood pressure dipping?