Article Figures & Data
Figures
- Figure 1
Study population screening, selection, and matching.
- Figure 2
Comparison of the mass of alcohol consumed per week by cases and controls.
Tables
- Table 1
Comparison of Age Groups, Medications, and Medical Conditions of Cases and Controls
Case Control P valuea Age Group 60-64 26 27 .86 65-69 20 18 .70 70-74 9 13 .35 75-79 13 9 .35 ≥80 2 3 .65 Medication No medication 15 13 .70 Anti hypertensive drugs Thiazides 2 4 .69 Calcium channel blockers 10 8 .63 Beta-blockers 20 13 .21 Loop diuretics 2 3 1 ACE/ARBs 18 11 .19 Potassium-sparing diuretics 2 4 .69 Centrally-acting agents 3 2 1 Association ACE/ARBs + thiazides 11 12 .82 Association ACE/ARBs + CCBs 5 2 .45 Association beta-blockers + thiazides 0 3 .25 Lipid lowering drugs Statin 22 23 88 Ezetrol 0 0 Inhalated medication Beta-mimetics 3 4 1 Anti-leukotriene 1 1 1 Medication (continued) Others Bisphosphonates 0 1 1 Anti-epileptic drug 0 1 1 NSAIDs 1 0 1 Proton pump inhibitor 11 11 1 Alpha-blocker 3 0 .25 Melatonin 0 0 Progestogen 1 0 1 Selective estrogen receptor modulator 0 0 GnRH analogue 0 0 Others 88 92 .75 Medical Conditions Hypertension 51 49 .71 Severe arteriopathy 2 1 1 Severe venous insufficiency 4 2 .68 Diabetes 14 12 .66 Hypothyroidy 9 7 .60 Hypoparathyroidy 0 1 1 Severe renal insufficiency 6 1 .11 Peripheral neuropathy 3 0 .24 Restless leg syndrome 1 0 1 Alcohol addiction 0 2 .50 Cancer (not in remission) 2 2 1 Others 55 59 .38 ACE = angiotensin-converting enzyme; ARB = angiotensin II receptor blocker; CCB = calcium channel blocker; GnRH = gonadatrophin-releasing hormone; NSAID = non-steroidal anti-inflammatory drug.
↵a P value were calculated using a χ2 test.
Supplemental Appendixes 1-5
Supplemental Apps 1-5
Files in this Data Supplement:
- Supplemental data: Appendixes 1-5 - PDF file
Annals Journal Club
Jul/Aug 2018: Association Between Alcohol Consumption and Nocturnal Leg Cramps
Elizabeth W. McIntosh, MD, Grant Family Medicine, and Michael E. Johansen, MD, MS, Associate Editor
The Annals of Family Medicine encourages readers to develop a learning community to improve health care and health through enhanced primary care. Participate by conducting a RADICAL journal club. RADICAL stands for Read, Ask, Discuss, Inquire, Collaborate, Act, and Learn. We encourage diverse participants to think critically about important issues affecting primary care and act on those discussions.1
HOW IT WORKS
In each issue, the Annals selects an article and provides discussion tips and questions. Take a RADICAL approach to these materials and post a summary of your conversation in our online discussion. (Open the article and click on "TRACK Discussion/ Submit a comment.") Discussion questions and information are online at: http://www.AnnFamMed.org/site/AJC/.
CURRENT SELECTION
Article for Discussion
Delacour C, Chambe J, Lefebrvre F, et al. Association between alcohol consumption and nocturnal leg cramps in patients over 60 years old: a case-control study. Ann Fam Med. 2018;16(4):296-301.
Discussion Tips
Case-control studies can be useful to explore associations when diseases are rare or not well understood.2 Nocturnal leg cramps are a common but relatively self-limited condition of unclear pathophysiology, although associations with various medications (such as diuretics and quinine) have been proposed. This case-control study explores an interesting and novel association between nocturnal leg cramps and alcohol consumption.
Discussion Questions
- What question is asked by this study and why does it matter to a family physician?
- What is a case-control study?2 How is this different from a cohort study?
- What are the strengths and weaknesses of a case-control study design to answer a study question?
- How did the researchers find cases and match to control subjects? How did the case and control groups compare in terms of demographics and medical history?
- What are the main study findings? How were these calculated? What was the credibility interval around the point estimate?
- To what degree might the findings be affected by:
- How patients were selected, excluded, or lost to follow-up?
- The size of the study? How many matches were included of the 4 different combinations (Supplemental Appendix 5)?
- How the main variable of alcohol consumption was measured and categorized?
- Confounding (false attribution of causality because 2 variables discovered to be associated actually are associated with a 3rd factor)?
- Chance?
- What is a dose-effect relationship? Did they find a dose-effect relationship with alcohol? Does this strengthen or weaken the findings of the study?
- How comparable is the study sample to patients in your practice with nocturnal leg cramps?
- Is this study likely to change your clinical practice? In what way?
- What are the next steps to further investigate these findings?
References
- Stange KC, Miller WL, McLellan LA, et al. Annals Journal Club: It's time to get RADICAL. Ann Fam Med. 2006;4(3):196-197. http://annfammed.org/content/4/3/196.full.
- Coggon D, Rose G, Barker DJP. Case-control and cross-sectional studies. In: Epidemiology for the Uninitiated. 4th ed. London, UK: The BMJ. https://www.bmj.com/about-bmj/resources-readers/publications/epidemiology-uninitiated/8-case-control-and-cross-sectional. Accessed Apr 12, 2018.
The Article in Brief
Association Between Alcohol Consumption and Nocturnal Leg Cramps in Patients Over 60 Years Old: A Case-Control Study
Chloé Delacour , and colleagues
Background Nocturnal leg cramps have a negative effect on patients' quality of sleep and quality of life. This study evaluates the association between nocturnal leg cramps and consumption of alcohol in older general practice patients.
What This Study Found Among patients over 60 years old, there is a strong association between consumption of alcoholic beverages and nocturnal leg cramps. In a case control study in France, 140 general practice patients with and without leg cramps were administered a food frequency questionnaire. Researchers found an association between global consumption of alcoholic beverages and nocturnal leg cramps. No relationship was found between amount of alcohol consumed and odds of leg cramps.
Implications
- The authors call for additional research to evaluate the existence of a causal link and to determine the pathophysiology of leg cramps and alcohol's impact on them.
