Markers of health and disease and pigmented spots in a middle-aged population.

DEAR EDITOR, Pigmented cutaneous spots, such as actinic/solar lentigines, develop with advancing age and are most commonly observed in chronically sun-exposed areas of the skin, such as the face, neck and dorsa of the hands. Actinic lentigines are characterized histopathologically by hyperpigmentation of the epidermal basal layer with an elongation of the epidermal rete ridges, and an increase in the number of dermal melanophages with deficient migration and digestive abilities. Other than cumulative ultraviolet (UV) exposure, risk factors for actinic lentigines are largely unknown. However, endocrine abnormalities, genetic factors, oestrogen levels, thyroid dysfunction and lower vitamin D levels have been identified as potential risk factors for some disorders of pigmentation (e.g. acanthosis nigricans, melasma and vitiligo). Thus there may be intrinsic factors that influence the development of common but benign pigmented spots such as actinic lentigines. In the present study, our purpose was to investigate the association between independent markers of health and disease and the extent of pigmented spots in a middle-aged Dutch white population. The research question was addressed using a cross-sectional study design embedded in a random subpopulation of the Leiden Longevity Study, with data available on markers of health and disease and on pigmented spots. For the analyses, participants were ranked into tertiles based on the measures investigated. The extent and severity of pigmented spots present were determined through grading of facial photographs by two expert dermatologists (T.W.G. and S.O.). A detailed description of the study design, recruitment, data collected and statistical analyses are reported in Appendix S1 (see Supporting Information). The study population (n = 623) had a mean age of 63 0 6 7 years, with 53 6% women (more characteristics are presented in Table S1; see Supporting Information). In statistical models comprising each determinant separately, a higher age and female sex, and (after adjusting for age and