From: BMC Musculoskelet Disord. 2010 Jul 30;11(1):171.
Metabolic syndrome has become increasingly common worldwide. Metabolic syndrome is a cluster of risk factors defined by high fasting glucose and triglycerides, low HDL cholesterol, high blood pressure, and abdominal obesity that increases the risk for cardiovascular diseases, type 2 diabetes mellitus, and all-cause mortality. The prevalence of metabolic syndrome in the US population is approximately 35%. In Eastern Finland the corresponding prevalence has been found to be 37%. Neck pain is also a common symptom among the middle-aged population. In a large Finnish population-based study, 24% of men and 37% of women aged at least 30 years had suffered from neck pain during the preceding month.
There are few studies in which the prevalence of pain has been assessed in subjects with metabolic syndrome. In one study females with chronic pain from fibromyalgia were at an increased risk of metabolic syndrome. Another study found that subjects with metabolic syndrome were more likely to have problems with pain symptoms. It has been suggested that stress is related to both metabolic syndrome and neck pain. Low physical activity has been found to be associated with metabolic syndrome and musculoskeletal pain. Some studies have found an association between obesity and neck pain. Because visceral obesity is one of the main features of metabolic syndrome, it could be proposed that metabolic syndrome is also related to neck pain. It has been speculated that both metabolic syndrome and persistent chronic pain syndromes are related to hypothalamus-pituitary-adrenal stress axis dysfunction. Therefore, it could be expected that the prevalence of neck pain is elevated in subjects with metabolic syndrome. Thus, if there were common features in the background of these disorders, the authors hypothesized that neck pain is more prevalent among subjects with metabolic syndrome than among those without metabolic syndrome. In this study the authors aimed to analyse the prevalence of neck pain in subjects with metabolic syndrome.
Neck pain was assessed by asking about neck pain during the preceding month. The presence of neck pain was dichotomized: (0) no neck pain or neck pain only occasionally and (1) daily or almost daily neck pain. Hence, in this study we regarded neck pain as daily or almost daily occurring neck pain.
This study showed that males and females with metabolic syndrome have an increased prevalence of neck pain. This association was stronger in males, but the prevalence of neck pain was higher in females. In accordance with previous studies, psychological distress was associated with neck pain especially in females. Although psychological distress was taken into account, metabolic syndrome was statistically associated with neck pain.
BMI was higher and waist circumference larger in males with neck pain. Previous studies have suggested that obesity is a risk factor of neck pain. Subjects with metabolic syndrome are often obese and waist size is among the criteria of metabolic syndrome. However, BMI and waist size were similar in females regardless of neck pain. Therefore, it is not plausible that the association between metabolic syndrome and neck pain is related solely to obesity. Compared with females, males with neck pain had higher cholesterol and triglyceride levels and a higher BMI. Psychological distress was associated with neck pain in both genders. However, a lower lever of distress was associated with neck pain in females, but in males only severe distress had that association. In general, the level of psychological distress was higher among females than among males. According to a large population-based study, concurrent psychological distress is more prevalent among females.
One background hypothesis for the connection between neck pain and metabolic syndrome found in this study is that there is a common factor resulting in the development of both neck pain and metabolic syndrome. Two such factors could be stress and physical inactivity. Stress has been suggested to be a risk factor of metabolic syndrome. A recent study has suggested that workers with neck, shoulder, or back pain have elevated levels of stress-related biomarkers. Further, it can be speculated that neck pain is an indicator of stress. A recent study has shown that in a specified population, physical inactivity is a risk of metabolic syndrome, whereas perceived stress was not associated with metabolic syndrome. The association between development of metabolic syndrome and low physical inactivity has also been shown in a previous study. A large epidemiological follow-up study indicated that physical inactivity is related to chronic musculoskeletal complaints. It has been suggested that chronic musculoskeletal pain is associated with cardiovascular-related mortality. Hence, physical inactivity may be an intervening factor between metabolic syndrome and neck pain. Further studies with a longitudinal setting could explore the potential causal association between neck pain and metabolic syndrome as well as the potential common background factors of neck pain and metabolic syndrome.
Metabolic syndrome was associated with neck pain. This association was stronger in males but the prevalence of neck pain was higher in females. Prospective studies focusing on the causal relationship between neck pain and metabolic syndrome are needed.
