Women who experience moderate to severe premenstrual syndrome (PMS) are significantly more likely than others to develop high blood pressure over the next 20 years, according to a new US study.
Up to 15 per cent of women have symptoms leading up to their menstrual periods that are severe enough to disrupt daily life.
PMS can include nausea, forgetfulness, dizziness, hot flashes, insomnia, depression or cramping that begin within 14 days before a period begins and can last a few days into the period.
PMS had not been linked to high blood pressure before, but they share many risk factors and likely share several mechanisms, said lead author Dr. Elizabeth R. Bertone-Johnson of the School of Public Health and Health Sciences at the University of Massachusetts Amherst and the Harvard School of Public Health in Boston.
Both conditions may involve dysfunction of the system that regulates fluid balance, blood volume and arterial constriction, Bertone-Johnson told Reuters Health by email.
"Obesity is a risk factor for both hypertension and PMS," she said. "Additionally, micronutrient deficiencies including vitamin D, calcium and other minerals and B vitamins have been related to both PMS and hypertension."
The researchers used questionnaire data from a subset of women in the long-term Nurses' Health Study II who had not reported PMS on their 1989 questionnaires.
More than 4,000 women reported a diagnosis of PMS between 1991 and 2005, and were sent a questionnaire about the occurrence of 26 physical or emotional symptoms.
"A large proportion of women may experience minor physical or emotional symptoms prior to the onset of their period each month, but this is not the same as clinically significant PMS," Bertone-Johnson said.
Overall, 1,275 of these women met the PMS criteria for this study, having at least one physical and one emotional symptom that was moderate or severe.
The researchers compared this group to 2,463 women who reported none or only mild menstrual symptoms.
By 2011, the study team found, 342 women with PMS reported having high blood pressure compared to 541 women without PMS. That translates to a rate of 2 cases of high blood pressure per 100 women per year among women with PMS and just 1.3 cases per 100 per year among women without PMS.
When the researchers accounted for age, smoking and body mass, women with PMS were 40 per cent more likely to develop high blood pressure, according to the results in the American Journal of Epidemiology.
Taking birth control pills or antidepressants did not appear to change this difference in risk.
"PMS is quite a complicated disorder, and likely has many contributing factors," Bertone-Johnson said. "Women affected are likely more sensitive to monthly fluctuations in estrogen and progesterone levels than other women, and to fluctuations in neurotransmitters regulating mood."
Obesity, smoking, early life abuse and chronic inflammation may also be involved, she said.
Risk of high blood pressure did seem to be reduced by high intake of the B vitamins riboflavin, thiamine and folate.
"We hypothesize that high intake of B vitamins may ameliorate a higher risk of hypertension associated with PMS by decreasing levels of homocysteine, a protein that adversely impacts blood vessel function and contributes to hypertension and heart disease," Bertone-Johnson said. "Higher B vitamin intake may also reduce chronic inflammation potentially associated with both PMS and high blood pressure."
Dairy, eggs, green leafy vegetables, lean meats and legumes are good sources of B vitamins.
Though these results should be confirmed in other studies, she said, there is little harm in screening women with clinically significant PMS for high blood pressure.
This study does not prove there is a causal relationship between PMS and high blood pressure, or that B vitamins ameliorate it, only that these factors may somehow be related, said Dr. Andrea Rapkin of the University of California, Los Angeles, who was not part of the new study.
"Significant PMS symptoms should be taken seriously and addressed with a tailored treatment programme," that will be unique to the individual, and may involve antidepressant medications, pain relievers, dietary changes and treatment for underlying conditions like irritable bowel syndrome or thyroid deficiencies, she said.