Ingrid Avidon

Reduced quality of life when experiencing menstrual pain in women with primary dysmenorrhea

Primary dysmenorrhea is the most common gynecological condition among women of reproductive age. Although dysmenorrhea has been reported to affect the ability of women to carry out daily activities, the impact of primary dysmenorrheic pain specifically on quality of life (QoL), has yet to be elucidated. We investigated whether QoL varies between women with and without severe primary dysmenorrhea, and whether QoL is impaired only during menstruation or also during pain‐free phases of the menstrual cycle. Twelve women with severe primary dysmenorrhea and nine control women completed the quality of life enjoyment and satisfaction questionnaire (Q‐LES‐Q‐SF) during menstruation and during the late follicular phase. Women with dysmenorrhea had a significant reduction in Q‐LES‐Q‐SF scores (mean ± SD: 54 ± 18%, percentage of the total maximum possible score) when they were experiencing severe menstrual pain compared with their own pain‐free follicular phase (80 ± 14%, p < 0.0001) and compared with controls during menstruation (81 ± 10%, p < 0.0001). They also rated their overall life satisfaction and contentment as poorer during menstruation. Severe menstrual pain associated with primary dysmenorrhea, therefore, impacts health‐related of QoL.

Does pain vary across the menstrual cycle? A review.

Reproductive hormones are implicated in moderating pain. Animal studies support both pronociceptive and antinociceptive actions of oestradiol and progesterone suggesting that the net effect of these hormones on pain is complex and likely depends on the interaction between hormones and the extent of fluctuation rather than absolute hormone levels. Several clinical pain conditions show variation in symptom severity across the menstrual cycle. Though, there is still no consensus on whether the menstrual cycle influences experimental pain sensitivity in healthy individuals. Comprehensive literature searches on clinical and experimental pain across the menstrual cycle, as well as gonadal hormones and pain were performed using the electronic databases PubMed, Google Scholar and the Cochrane Library. Full‐text manuscripts were reviewed for relevancy and reference lists were cross‐checked for additional relevant studies. Most of the more recent, well‐controlled studies show that menstrual cycle phase has no effect on the perception of pain in healthy, pain‐free women. Although recent studies investigating pain‐related brain activation have shown differential activation patterns across the menstrual cycle in regions involved with cognitive and motor function, even in the absence of a behavioural pain response, suggesting that cognitive pain and bodily awareness systems are sensitive to menstrual cycle phase. The interaction between the gonadal hormones and pain perception is intricate and not entirely understood. We suggest further investigations on the association between female reproductive hormones and pain sensitivity by exploring the interaction between clinical and experimental pain and the hormone changes that characterize puberty, post‐partum and the menopause transition.

Women with dysmenorrhea are hypersensitive to experimental deep muscle pain across the menstrual cycle.

UNLABELLED Primary dysmenorrhea is a common painful condition in women that recurs every month across the reproductive years. The recurrent nociceptive input into the central nervous system that occurs during menstruation each month in women with dysmenorrhea is hypothesized to lead to increased sensitivity to painful stimuli. We investigated whether women with primary dysmenorrhea are hyperalgesic to deep muscle pain induced by a cleanly nociceptive method of hypertonic saline injection. Pain stimulation was applied both within an area of referred menstrual pain (lower back) and at a remote site outside of referred menstrual pain (forearm) in 12 healthy women with severe dysmenorrhea and 9 healthy women without dysmenorrhea, at 3 phases of the menstrual cycle: menstruation and follicular and luteal phases. Women rated their pain severity on a 100-mm visual analog scale every 30 seconds after injection until the pain subsided. In both groups of women, menstrual cycle phase had no effect on the reported intensity and duration of muscle pain. However, women with dysmenorrhea had increased sensitivity to experimental muscle pain both at the site of referred pain and at a remote nonpainful site, as assessed by peak pain severity visual analog scale rating, area under the visual analog scale curve, and pain duration, compared to women without dysmenorrhea. These data show that women with severe primary dysmenorrhea, who experience monthly menstrual pain, are hyperalgesic to deep muscle pain compared to women without dysmenorrhea. PERSPECTIVE Our findings that dysmenorrheic women are hyperalgesic to a clinically relevant, deep muscle pain in areas within and outside of referred menstrual pain indicates lasting changes in pain sensitivity outside of the painful period during menstruation.

A two-year history of high bone loading physical activity attenuates ethnic differences in bone strength and geometry in pre-/early pubertal children from a low-middle income country.

We examined the interplay between ethnicity and weight-bearing physical activity on the content and volumetric properties of bone in a pre- to early pubertal South African Black and White population. Sixty six children [Black boys, 10.4 (1.4)yrs, n=15; Black girls, 10.1 (1.2)yrs, n=27; White boys, 10.1 (1.1)yrs, n=7; White girls, 9.6 (1.3)yrs, n=17] reported on all their physical activities over the past two years in an interviewer administered physical activity questionnaire (PAQ). All participants underwent a whole body and site-specific DXA scan and we also assessed bone structure and estimated bone strength with pQCT. Children were classified as being either high or low bone loaders based on the cohorts median peak bone strain score estimated from the PAQ. In the low bone loading group, Black children had greater femoral neck bone mineral content (BMC) (2.9 (0.08)g) than White children (2.4 (0.11)g; p=0.05). There were no ethnic differences in the high bone loaders for femoral neck BMC. At the cortical site, the Black low bone loaders had a greater radius area (97.3 (1.3) vs 88.8 (2.6)mm(2); p=0.05) and a greater tibia total area (475.5 (8.7) vs. 397.3 (14.0)mm(2); p=0.001) and strength (1633.7 (60.1) vs. 1271.8 (98.6)mm(3); p=0.04) compared to the White low bone loaders. These measures were not different between the Black low and high bone loaders or between the Black and White high bone loaders. In conclusion, the present study shows that there may be ethnic and physical activity associations in the bone health of Black and White pre-pubertal children and further prospective studies are required to determine the possible ethnic specific response to mechanical loading.

Whole body vibration increases hip bone mineral density in road cyclists.

This study aimed to determine the effects of 10 weeks of whole body vibration training on the bone density of well-trained road cyclists. 15 road cyclists were assigned to either a vibrating group (n=8), who undertook 15 min of intermittent whole body vibration at 30 Hz, 3 times per week while continuing with their normal cycling training; or a control group (n=7), who continued with their normal cycling training for the 10-week period. Cyclists were age, body mass and height matched with 15 sedentary participants. At baseline, all participants underwent regional dual x-ray absorptiometry scans, where both cycling groups had lower pelvic (p<0.050) and higher head bone mineral density (p<0.050) than the sedentary participants with no other differences observed. After 10 weeks of training, vibrating cyclists showed a significantly greater increase in hip bone mineral density (0.020±0.010 g.cm - 2 (1.65%), p=0.024) while the control cyclists ( - 0.004±0.001 g.cm - 2 (0%)) showed no change (p>0.050). The control group had a significantly lower spine bone mineral density (1.027±0.140 g.cm - 2, p=0.020) compared to baseline (1.039±0.140 g.cm - 2). This loss was not observed in the vibrating group. 10 weeks of whole body vibration training increased hip and preserved spine bone mineral density in road cyclists.

Women with dysmenorrhoea are hypersensitive to experimentally induced forearm ischaemia during painful menstruation and during the pain-free follicular phase.

Monthly primary dysmenorrhoeic pain is associated with increased sensitivity to painful stimuli, particularly in deep tissue. We investigated whether women with dysmenorrhoea, compared with controls, have increased sensitivity to experimentally induced deep‐tissue muscle ischaemia in a body area distant from that of referred menstrual pain.

Bone resorption is suppressed immediately after the third and fourth days of multiday cycling but persistently increased following overnight recovery

Previous studies suggest that seasoned cyclists may incur a low bone mineral density. This study investigated the effect of multiday cycling on bone turnover. Ten male cyclists completed 4 consecutive days of cycling for 3 h·day(-1). Sweat calcium excretion during exercise and serum calcium, cortisol, bone formation marker (bone alkaline phosphotase (bone-ALP)), bone resorptive marker (C-terminal telopeptide of type I collagen (β-CTX)), and parathyroid hormone concentration were measured before and immediately postexercise each day. Serum β-CTX concentration increased from pre- to postcycling on days 1 and 2 (p = 0.01) (day 1: 0.31 ± 0.14 to 0.60 ± 0.4 ng·mL(-1); day 2: 0.58 ± 0.26 to 0.87 ± 0.42 ng·mL(-1)), while serum bone-ALP concentration remained unchanged. Conversely, on days 3 and 4 both serum β-CTX (day 3: 0.60 ± 0.26 to 0.43 ± 0.26 ng·mL(-1), p < 0.05; day 4: 0.63 ± 0.21 to 0.43 ± 0.22 ng·mL(-1), p < 0.001) and bone-ALP (p < 0.01) response to exercise was suppressed. Interestingly, calcium lost to sweat and postexercise serum cortisol concentration were also significantly lower on days 3 and 4 than on day 1 (p < 0.05). However, both serum β-CTX (102%-124%) and bone-ALP (25%-29%) remained persistently elevated after 21 h of overnight recovery on all successive days compared with day 1 pre-exercise, where the percentage increase was greater for β-CTX (p < 0.05). Bone resorption, immediately following prolonged cycling, is acutely reduced by the third and fourth consecutive days and is coincident to reduced sweat calcium excretion and cortisol concentration. However, multiday cycling imposes a persistent increase in bone resorption following overnight recovery.

Anaerobic Power in Road Cyclists Is Improved After 10 Weeks of Whole-body Vibration Training

Abstract Oosthuyse, T, Viedge, A, McVeigh, J, and Avidon, I. Anaerobic power in road cyclists is improved after 10 weeks of whole-body vibration training. J Strength Cond Res 27(2): 485–494, 2013—Whole-body vibration (WBV) training has previously improved muscle power in various athletic groups requiring explosive muscle contractions. To evaluate the benefit of including WBV as a training adjunct for improving aerobic and anaerobic cycling performance, road cyclists (n = 9) performed 3 weekly, 10-minute sessions of intermittent WBV on synchronous vertical plates (30 Hz) while standing in a static posture. A control group of cyclists (n = 8) received no WBV training. Before and after the 10-week intervention period, lean body mass (LBM), cycling aerobic peak power (Wmax), 4 mM lactate concentration (OBLA), V[Combining Dot Above]O2peak, and Wingate anaerobic peak and mean power output were determined. The WBV group successfully completed all WBV sessions but reported a significant 30% decrease in the weekly cycling training time (pre: 9.4 ± 3.3 h·wk−1; post: 6.7 ± 3.7 h·wk−1; p = 0.01) that resulted in a 6% decrease in V[Combining Dot Above]O2peak and a 4% decrease in OBLA. The control group reported a nonsignificant 6% decrease in cycling training volume (pre: 9.5 ± 3.6 h·wk−1; 8.6 ± 2.9 h·wk−1; p = 0.13), and all measured variables were maintained. Despite the evidence of detraining in the WBV group, Wmax was maintained (pre: 258 ± 53 W; post: 254 ± 57 W; p = 0.43). Furthermore, Wingate peak power increased by 6% (668 ± 189 to 708 ± 220 W; p = 0.055), and Wingate mean power increased by 2% (553 ± 157 to 565 ± 157 W; p = 0.006) in the WBV group from preintervention to postintervention, respectively, without any change to LBM. The WBV training is an attractive training supplement for improving anaerobic power without increasing muscle mass in road cyclists.

Changes in substrate utilisation and protein catabolism during multiday cycling in well-trained cyclists

Abstract There is a paucity of studies that have evaluated substrate utilisation and protein catabolism during multiday strenuous exercise in athletes. Eleven well-trained male cyclists completed 3 h of race-simulated cycling on 4 consecutive days. Cyclist exercised 2 h postprandially and with carbohydrate supplementation (~50 g · h−1) during exercise. Whole body substrate utilisation was measured by indirect calorimetry, protein catabolism from sweat and urine urea excretion, and blood metabolite concentration was evaluated. Protein catabolism during exercise was significantly greater on days 2–4 (29.9 ± 8.8; 34.0 ± 11.2; 32.0 ± 7.3 g for days 2, 3, and 4, respectively) compared to day 1 (23.3 ± 7.6 g), P < 0.05. Fat oxidation was greater at 21 km (~45 min) on days 2–4 (1.06 ± 0.23; 1.08 ± 0.25; 1.12 ± 0.29 g · min−1) compared to day 1 (0.74 ± 0.23 g · min−1, P < 0.05), but the rate of carbohydrate and fat oxidation was similar between days at 50 and 80 km. Whole body substrate utilisation is altered on subsequent days of multiday prolonged strenuous cycling that includes a quicker transition to greater fat utilisation from exercise onset and a 28–46% greater reliance on endogenous protein catabolism on all successive days.