Complex sentence: The initial Whitehall study found lower grades, and thus status, were clearly associated with greater propensities for significant risk factors, including obesity, smoking, reduced leisure time and physical activity, more baseline illness, higher blood pressure, and shorter height.
Split into simpler sentences: The initial Whitehall study found lower grades, and thus status, were clearly associated with higher prevalence of significant risk factors. These risk factors include obesity, smoking, reduced leisure time, lower levels of physical activity, higher prevalence of underlying illness, higher blood pressure, and shorter height.